Light and Dark Sides of Sustainability Image: Consumer Perceptions of Brand Ethics

1. Introduction

In recent decades, sustainability has emerged as a central issue in both academic research and managerial practice, driven by increasing concerns about environmental degradation, social inequality, and the long-term impacts of business activities on society. Consumers are becoming progressively more informed and demanding, expecting brands not only to deliver functional value but also to demonstrate ethical behaviour, transparency, and responsibility toward environmental and social challenges. As a result, sustainability has evolved from a peripheral corporate initiative into a strategic dimension that significantly shapes brand reputation and competitive advantage.

Recent research highlights that consumer trust in sustainable brands is shaped by a combination of perceived value, customer satisfaction, customer service quality, and brand image, underscoring the multifaceted nature of trust formation (Chkoniya, 2025). Furthermore, sustainability-oriented brand communication has been identified as a decisive driver of brand image, ultimately reinforcing consumers’ trust in the brand (Monfort et al., 2025) A green brand image can be understood as a multidimensional construct shaped by consumers’ evaluations of a firm’s capabilities, ethical orientation, social responsibility practices, and long-term commitment to sustainability (Amron, 2018).

Despite the growing adoption of sustainable marketing practices and the expansion of non-financial reporting frameworks such as Environmental, Social, and Governance (ESG), the effectiveness of these initiatives remains highly dependent on how consumers perceive them. Their perception of brand authenticity enhances green brand trust, indicating that trust increases when they believe a brand’s environmental claims are sincere and consistently demonstrated. Even when consumers respond favourably to green advertising or view the brand as genuinely eco-friendly, these perceptions only drive purchase behaviour if they foster trust; without it, positive impressions alone may not lead to action (Thao et al., 2025).

Although the existing literature has extensively explored sustainability and marketing separately, there remains a need for integrative research that critically examines how a brand’s sustainability image shapes consumers’ ethical perceptions of the brand. Addressing this gap, the present study aims to synthesise and analyse existing academic research on sustainable marketing and brand sustainability image to provide a clearer understanding of their influence on consumer perceptions. By doing so, this article contributes to the ongoing debate over how brands can build ethical legitimacy and long-term value through credible, consistent sustainability strategies.

2. Methodology

This study adopts a qualitative research design grounded in a comprehensive literature review, with the primary aim of synthesising and critically analysing existing academic research on sustainable marketing, brand sustainability image, and consumer behaviour. By systematically examining the current body of knowledge, the study seeks to provide a coherent understanding of how brands’ sustainability initiatives influence consumer perceptions, particularly regarding ethical and responsible business practices.

A systematic search strategy was employed to identify relevant academic sources by retrieving peer-reviewed journal articles, conference papers, and book chapters from multiple electronic databases, including Scopus, Web of Science, and Google Scholar. Inclusion criteria focused on studies published within the last 10 years, addressing empirical and theoretical contributions relevant to the research question. Selected publications were carefully screened and analysed to draw insights into the relationship between a brand’s sustainability image and its ethical perception among consumers. Grammarly (2024) is used to improve the readability and language of the work. This approach enables the study to answer the central research question: How does a brand’s sustainability image shape its ethical perception?

3. New Marketing Trends

Understanding new marketing trends is essential to contextualise how sustainability and ethics have become central elements of brand value creation in contemporary markets. Contemporary marketing is undergoing major change, driven by digitalisation and a growing consumer demand for companies to maintain ethical and social responsibility. This evolution reflects a paradigm shift in which technology and brand purpose merge to create value in a globalised, constantly changing market. Guatemala Mariano et al. (2023) argue that modern digital marketing should focus on the “creation of social value through the strategic use of digital platforms”. This perspective reinforces the need for brands to move beyond simple commercial transactions by adding value to customers and fostering loyalty, especially in highly competitive markets where products are no longer merely objects of physical consumption but vehicles of added value.

This evolution reflects a paradigm shift in which brand transparency and ethical image are determining factors in modern consumers' perceptions. As Kotler and Armstrong (2023) argue, marketing is not limited to a sales function but rather to the process of creating value for customers sustainably and building strong relationships to capture that value in return. One of the currently dominant trends is personalisation, both product and the service itself, allowing brands to abandon mass-scale communication and favour individualised and personalised interactions, which become highly relevant for creating a good brand image and fostering customer loyalty. The effectiveness of this trend lies in anticipating consumer needs and desires even before they are explicitly expressed. These trends reshape not only how brands communicate, but also how consumers evaluate brands’ ethical credibility and social responsibility.

Sustainability in marketing is no longer limited to the environmental dimension; it now encompasses social responsibility, diversity, and representativeness. Currently, non-financial information is structured around the Environmental, Social, and Governance pillars, which function as critical tools for stakeholders to assess risk and the long-term sustainability of companies (Kaya et al., 2025). The disclosure of these practices has ceased to be a mere exercise in transparency and has become a factor that directly influences brand reputation and market trust (Kaya et al., 2025). In this context, the inclusion of themes such as gender, racial, or economic diversity functions as a powerful marketing tool and can contribute to a positive brand image. Advertising appeals focused on social causes significantly influence behavioural intentions through the mediation of self-expression value and perceived brand authenticity (Pham Thi Be et al., 2024). Thus, when these campaigns are perceived as authentic rather than merely commercial exploitation, they can substantially improve the overall brand image.

4. Sustainable Marketing

The concept of sustainable marketing has increasingly established itself as a key concept, reflecting the need to incorporate environmental and social concerns into business strategies without compromising the creation of economic value. According to Mahmoud (2016), a sustainable market orientation contributes positively to companies’ social and economic performance, particularly in emerging markets. Fracarolli Nunes et al. (2024) also support this perspective, stating that sustainable marketing can positively influence business performance, especially in the long term. Despite the growing interest in sustainable marketing, there remains a limited understanding of how sustainability initiatives translate into consumer trust, ethical perceptions, and long-term brand loyalty, particularly in contexts where greenwashing risks are present(Ozdemir, 2025).

In this line of thought, Lim (2022) states that sustainable marketing can be understood as a strategic approach that guides the responsible formulation, communication, and delivery of value while promoting social well-being, environmental protection, and long-term organisational performance. This perspective highlights a shift from marketing focused exclusively on consumers to a more comprehensive model oriented toward stakeholders and the principles of sustainable development. Therefore, sustainable marketing is not limited to product and service promotion; it also involves structural changes in how companies define their objectives, interact with the market, and assume responsibility toward society.

Sustainable marketing strategies aim to create economic and social value on an ongoing basis by integrating environmental and social concerns throughout the production process. According to Kumar et al. (2022), sustainable marketing plays a central role in promoting responsible consumer behaviour and building sustainable competitive advantage by aligning business objectives with the growing expectations of consumers and society. The authors argue that companies that integrate sustainability into their marketing strategies tend to strengthen consumer trust, enhance corporate reputation, and increase brand loyalty.

Regarding the future of sustainable marketing, Feio (2016) argues that one of the most evident links between marketing and sustainability is reflected in the growing number of organisations that incorporate sustainable practices into their strategies, to differentiate themselves from competitors and strengthen their corporate reputation and image in relation to social and environmental dimensions. In line with this author, the most recurrent marketing strategies adopted by sustainability-oriented companies can be systematised as follows:

• Systemic perspective: Organizations assess performance by considering interrelationships among internal components and stakeholders.

• Long-term Triple Bottom Line approach: Economic, social, and environmental dimensions are jointly balanced through strategic trade-offs.

• Stakeholder involvement: Stakeholders are actively engaged in decision-making and value creation.

• Life-cycle cost integration: Costs and impacts are evaluated across the entire product or service life cycle.

• Trust-based communication: Transparency and long-term relationships guide communication and market interactions.

However, the growing importance of sustainability in marketing has also led to less ethical practices, namely greenwashing. Greenwashing occurs particularly when companies make environmental commitments that significantly exceed their actual practices (Delmas et al., 2011), leading to disclosures that do not reflect reality and tend to mislead consumers. As explained by Zhang et al (2023), greenwashing acts as a destructive factor that negatively impacts purchase intention, primarily by eroding consumer trust.

Such behaviour can negatively affect the organisations that engage in it. For example, when a company publishes a negative sustainability report, it may become the target of criticism for its involvement in “green advertising” due to ethical concerns arising from the discrepancy between promotional claims and actual performance (Nyilasy et al., 2014). Moreover, the negative effects of greenwashing are not limited to the companies that adopt such practices but also extend to organisations that act in a genuinely ethical manner and make consistent efforts towards environmentally responsible behaviour, as it undermines overall trust in sustainability-oriented marketing practices (Nyilasy et al., 2014).

Beyond ethical concerns, implementing sustainable marketing strategies faces broader challenges. According to Gu and Wang (2022), one of the fundamental challenges is the need for organisations to balance the dimensions of the Triple Bottom Line (TBL), harmonising economic growth with ecological protection and social responsibility. This transition requires a high level of innovation and continuous investment in technical Research and Development. Moreover, the viability of these projects is strongly dependent on the level of financial development and the institutional support available, making sustainability a high-risk, high-cost endeavour for companies.

5. Brand Sustainability Image

According to Jagani et al (2025), sustainable brand image is the overall perception consumers form of a brand, resulting from their experiences, beliefs, emotions, and knowledge, particularly regarding the brand’s commitment to sustainability (Kotler et al., 2024). Within this framework, legitimacy theory holds that organisations gain positive perceptions among their stakeholders when their practices align with prevailing social expectations (Suchman, 1995). In the contemporary business context, sustainability plays a central role in these expectations, with the implementation of concrete, verifiable sustainable practices a determining factor in the construction of organisational legitimacy and in the strengthening of a credible sustainable brand image. To assess sustainable brand image in greater depth, the main dimensions that contribute to its construction will be analysed below.

5.1. Consumers’ Perception of Sustainability as Part of Brand Identity

Consumers increasingly evaluate brands through sustainability, incorporating environmental and social practices into the overall perception of brand identity. Jagani et al (2025) show that a company’s orientation toward sustainability improves brand image only when it is translated into existing sustainable implementation. When actions do not accompany orientation, their effect on the image may be null or even negative, as it can generate cognitive dissonance.

In a complementary way, Tran et al (2025) demonstrate that green brand image and perceived brand authenticity reinforce green brand trust, which, in turn, increases the intention to purchase sustainable products. In contrast, perceptions of greenwashing significantly reduce these intentions. Together, these results suggest that consumers begin to see sustainability as a central part of brand identity when it is credibly incorporated into practices and communications, rather than merely as a superficial positioning tool.

5.2. Eco-Friendly Packaging and Sustainable Design

Nowadays, eco‑friendly packaging is one of the most visible signals of a brand's commitment to sustainability, especially among younger consumers. According to (Plotkina et al., 2025), different types of sustainable packaging, such as recyclable, reusable and biodegradable, generate distinct perceptions and can either strengthen or weaken the green brand image depending on the degree of consistency with consumers’ environmental expectations. Beyond the material itself, sustainable design, which includes shape, graphics, messages, and functionality, also plays a significant role in creating value and consolidating brand image (Li & Lin, 2024).

Hallez et al (2025) further add that simply labelling packaging as “sustainable”, for example, through the use of cardboard instead of plastic, or by displaying environmental concerns on the package, increases the perceived sustainability and may influence the evaluation of product attributes (health, taste, convenience), even though this effect does not always automatically transfer to the overall perception of the brand. According to Calabrese et al (2018) and (Han, 2021), sustainability is important not only for improving operational efficiency but also for building a positive brand image. However, as highlighted by Jagani et al. (2025), translating these efforts into a sustainable brand image can be demonstrated through concrete, visible changes to the product.

In companies, perceptions of sustainability are also related to communication, employee behaviour, and customer experiences, making them more vulnerable to perceptions of greenwashing when environmental claims are seen as exaggerated or misleading (Akturan, 2018; Delmas et al., 2011; Jagani et al., 2024). Thus, according to Jagani et al. (2025), building a credible, sustainable brand image requires strong consistency between discourse and practice, as well as between environmental and social initiatives and how they are communicated to stakeholders.

5.3. Transparency and Sustainability Certification as Trust Builders

Transparency and sustainability statements are crucial to transforming green communication into consumer trust and a credible, sustainable brand image. Tran et al (2025) show that receptivity to green advertising, green brand image, and perceived brand authenticity positively influence green brand trust. The authors’ model highlights green brand trust as a mediator, suggesting that even persuasive green messages depend on credible, consistent content to build trust and purchase intention. Jagani et al (2025) complement this perspective by demonstrating that sustainability implementation mediates the relationship between sustainability orientation and brand image, suggesting that transparency (for example, through certifications or reports) provides the necessary evidence to avoid perceptions of greenwashing and legitimise the brand’s sustainability claims.

Wu et al (2025) add an important dimension to this discussion by showing that green influencers act as transparency agents in brands’ sustainability communication. According to the authors, through transparent, clear communication, green influencer marketing can effectively convey information about sustainable consumption, reducing information asymmetry between brands and consumers. The study shows that green consumer trust acts as a mediating variable between green influencers’ communication and green brand image, indicating that trust is the mechanism through which sustainability messages translate into positive brand perceptions.

5.4. Ecological Storytelling

Ecological storytelling refers to the narratives that brands construct around their environmental practices, values, and impacts, whether in advertising, digital communication, or social media. Tran et al (2025) analyse receptivity to green advertising as consumers’ responses to these narratives and show that when green messages are perceived as credible and relevant, they contribute to a stronger green brand image, greater authenticity, and higher levels of green brand trust. In contrast, when ecological storytelling is vague or exaggerated, it increases perceptions of greenwashing, thereby directly reducing green purchase intention, even among consumers sensitive to environmental issues.

Wu et al (2025) add to this perspective by introducing green influencers as central narrators of ecological storytelling in digital environments. The authors show that, through transparent, detailed, and consistent communication about sustainable consumption, green influencers can reduce information asymmetry between brands and consumers, thereby strengthening green consumer trust. Thus, ecological storytelling, whether produced by brands or influencers, serves as a critical mechanism for transforming sustainability initiatives into symbolic meaning, provided it maintains coherence with actual practices. It minimises the risk of greenwashing, which Tran et al (2025) identify as destructive to purchase intention.

6. Sustainability Image as a Source of Ethical Legitimacy

6.1. Ethical Brand Perception

Ethical brand perception is a central element in building reputation and strengthening consumer engagement within sustainable digital marketing contexts. According to Odoom (2025), consumers evaluate brands not only on the products they offer but also on their moral integrity, social and environmental responsibility, and ethical consistency throughout the entire value chain. At the core of ethical brand perception lies the moral integrity of the brand, which refers to the consistency between the values an organisation communicates and the practices it actually implements. This coherence between discourse and action is essential for building trust and strengthening brand reputation, leading consumers to perceive brands as more credible and authentic when they consistently adopt ethical behaviours (Odoom, 2025) Additionally, Rocha et al (2024) demonstrate that the adoption of ethical and socially responsible practices is associated with better organisational outcomes, suggesting that moral integrity is not only a reputational factor but also a strategic element that contributes to companies' economic performance.

The ethical assessment of the brand is not limited to the final product offered to consumers; it extends across all stages of the value chain. As highlighted by Odoom (2025), consumers increasingly value aspects such as the origin of raw materials, production processes, working conditions and the social and environmental impacts of operations. Consequently, a lack of transparency in these areas may compromise the brand's ethical perception, even when the final product is presented as sustainable. Complementarily, Rocha et al (2024) show that integrating responsible practices throughout the value chain creates both economic and social value, reinforcing companies’ legitimacy among their stakeholders. In this context, a comprehensive ethical approach that considers not only the final product but also the underlying processes and broader impacts is essential for avoiding perceptions of greenwashing and for strengthening the brand's authenticity and reputation (Odoom, 2025; Rocha et al., 2024).

6.2. Authenticity and Legitimacy: Foundations of Ethical Brand Acceptance

The Theory of Legitimacy holds that organisations seek to align their actions with socially accepted expectations to maintain or reinforce their social acceptance. According to Guiry (2024), legitimacy acts simultaneously as a “source of power and a constraint on power,” conditioning the behaviour and actions of organisations. The application of the Theory of Legitimacy in marketing is based on the principle that an organisation's survival depends on maintaining its social brand and interacting with the community in which it operates. According to Daromes et al (2023), this corporate legitimacy is consolidated when the entity’s actions are perceived as “highly desirable, appropriate, or appropriate in some socially constructed system of norms, values, beliefs, and definitions.” Additionally, companies adopt non-financial reporting standards and sustainability practices to enhance their legitimacy in the eyes of stakeholders.

However, when this adherence is limited to appearance and fails to translate into concrete actions, greenwashing occurs. Thus, the Theory of Legitimacy helps to understand that the disclosure of non-financial information can be both an instrument of real transparency and a symbolic strategy of social conformity, used to protect organisational reputation in an increasingly demanding institutional environment. As demonstrated by Daromes et al (2023), there is a joint impact whereby “the achievement of the company's financial performance needs public support or recognition through CSR disclosure, which in turn influences firm value,” showing that profit is only fully validated by investors when the company demonstrates that it is socially responsible through the disclosure of its sustainability practices. Napoli et al. (2014) highlight authenticity as a key criterion through which consumers evaluate brands’ ethical claims. When sustainability initiatives are perceived as authentic, they are more likely to be interpreted as credible and morally consistent expressions of the brand’s values, thereby reinforcing perceptions of social appropriateness and ethical legitimacy.

6.3. Trust as the Pillar of Ethical Legitimacy

In a context where sustainability has become a central concern for consumers, brands that adopt and demonstrate responsible, sustainable practices tend to be perceived as more benevolent and ethically grounded, thereby reinforcing perceptions of integrity. Brand image, therefore, goes beyond a simple reflection of consumer perceptions and functions as a key mechanism in the construction of trust (Monfort et al., 2025) Trust plays a critical role in reducing perceptions of risk and scepticism in sustainability communication, as it legitimises a brand’s ethical positioning. When brands consistently fulfil their stated commitments, consumers are more likely to view them as reliable and principled, which strengthens trust over time (Monfort et al., 2025; Erdem et al., 2004). Brand trust emerges not only from perceptions of competence and benevolence but also from the extent to which a brand’s actions are congruent with consumer expectations, particularly regarding sustainability and social responsibility (Clemente-Mediavilla et al., 2018).

When consumers trust a brand, they are more inclined to accept its sustainability image as a genuine expression of ethical responsibility, thereby strengthening the brand’s social acceptance and reinforcing its legitimacy. Prior research further indicates that a favourable brand image enhances consumer trust by signalling alignment with consumers’ expectations and core values (Sharma et al., 2019). Therefore, trust can be understood as the central link through which the sustainability image translates into ethical legitimacy. A sustainability-oriented brand image serves as a heuristic cue, reducing consumers’ uncertainty about the authenticity of corporate actions and allowing them to infer ethical intentions even in the absence of complete information. In this sense, credibility and demonstrated corporate competence, especially in the implementation of sustainable initiatives, play a decisive role in facilitating and consolidating brand trust (Sichtmann, 2007).

6.4. Sustainability as a Moral Signal

Empirical evidence suggests that brand image serves as a mediating factor between perceived social sustainability and consumers’ willingness to pay a premium, as socially responsible positioning strengthens brand reputation and positively shapes price perceptions (Leong et al., 2026). Brands that actively demonstrate their commitment to social and environmental causes do not merely signal quality or status; they convey moral values, serving as a moral signal that consumers interpret as an indication of ethical integrity. This signalling effect can enhance consumer trust and foster a sense of shared values, further reinforcing their willingness to pay a premium.

Corporate Social Responsibility functions as a strategic mechanism through which firms contribute to societal well-being and environmental preservation, thereby reinforcing brand image and consolidating corporate reputation (Le et al., 2024). When sustainability is communicated as a moral imperative rather than a purely marketing strategy, it strengthens the brand's perception as ethically responsible, aligning corporate actions with consumer expectations of fairness, responsibility, and social contribution. In increasingly competitive markets, a strong commitment to sustainability has become a fundamental requirement for long-term organisational viability rather than a discretionary strategic option (Azmat et al., 2023). In sum, sustainability serves as a moral signal that reinforces the brand's ethical evaluation, translating its commitments into meaningful ethical cues for consumers. When interpreted as credible and value-driven, this signal reinforces the brand’s moral standing and supports its ethical legitimacy in the marketplace.

7. Discussion

This study examined how a brand’s sustainability image shapes consumers’ ethical perception of the brand by synthesising existing research on sustainable marketing, brand image, authenticity, trust, and legitimacy. The analysis demonstrates that the sustainability image does not operate as an isolated construct, but as part of a broader evaluative process through which consumers assess brands’ moral integrity, credibility, and social appropriateness. In this process, sustainability image functions as an initial cognitive and symbolic cue that signals a brand’s ethical orientation and commitment to responsible practices (Odoom, 2025; Rocha et al., 2024). However, its effectiveness depends critically on perceptions of authenticity and consistency between communicated values and actual practices across the value chain (Jagani, 2025; Tran et al., 2025).

The reviewed literature highlights authenticity as a necessary condition for a sustainable image to contribute to ethical legitimacy. When sustainability initiatives are perceived as genuine and substantively implemented, they align brands with socially constructed norms and expectations, reinforcing their legitimacy (Napoli et al., 2014; Daromes et al., 2023). In contrast, when sustainability communication lacks substantive support, consumers are more likely to interpret it as symbolic or opportunistic, leading to perceptions of greenwashing that undermine ethical acceptance (Delmas, 2011; Nyilasy et al., 2014). Trust emerges as the central mechanism in this relationship (Monfort et al., 2025; Clemente-Mediavilla et al., 2018). By signalling alignment with widely shared social and environmental values, a sustainability-oriented brand image reduces uncertainty regarding the brand’s intentions and fosters confidence in the authenticity of its actions (Sharma et al., 2019; Sichtmann, 2007). This trust mitigates scepticism and enables consumers to interpret sustainability initiatives as morally grounded rather than strategically motivated (Erdem et al., 2004).

This perspective shifts the focus from sustainability as a communication strategy to sustainability as an ethically evaluative process embedded in consumer judgment. As ethical perceptions consolidate, trust allows consumers to attribute ethical legitimacy to the brand, granting it social acceptance and moral approval within its broader institutional and societal context (Guiry, 2024; Suchman, 1995). Ultimately, sustainability serves as a moral signal whose legitimacy depends on the dynamic interplay among authenticity, trust, and consistent practice (Leong et al., 2026; Azmat et al., 2023). Brands seeking to build durable ethical legitimacy must therefore move beyond symbolic sustainability claims and adopt coherent, transparent, and value-driven strategies that consistently align communication with action (Kotler et al., 2023; Jagani et al., 2025).

While these mechanisms highlight the potential of sustainability as a moral signal, the practical impact of such initiatives may be moderated by behavioural and structural constraints. Consumers may express ethical intentions yet hesitate when higher costs or inconveniences are involved, revealing an intention–behaviour gap (Lim, 2023). Similarly, governmental or organisational sustainability initiatives may not fully restructure the economic systems that drive overconsumption, limiting the broader societal effect of these practices (Spangenberg, 2014). These observations suggest that although a sustainability image can strongly influence ethical perceptions, its translation into concrete behavioural or systemic outcomes is contingent on contextual factors beyond the brand’s immediate control. By integrating sustainability image, authenticity, trust, and ethical legitimacy into a unified analytical framework, this study contributes to the literature by clarifying the mechanisms through which sustainability acquires moral meaning in consumers’ evaluations.

In summary, a brand’s sustainability image shapes its ethical perception by serving as a visible, interpretable signal of the brand’s moral orientation, through which consumers evaluate whether its actions align with accepted social and environmental norms. When sustainability is perceived as authentic and consistently implemented, it fosters trust and enables consumers to interpret the brand’s behaviour as ethically appropriate and socially responsible (Napoli et al., 2014; Monfort et al., 2025). Thus, the sustainability image should be understood not merely as a reputational asset, but as a normative signal through which brands are morally assessed and socially legitimised.

8. Conclusion

In conclusion, this research highlights that sustainability has evolved from a peripheral corporate initiative into a central strategic dimension that shapes brand reputation and competitive advantage in the modern world. By integrating sustainability image, ethical legitimacy, authenticity, and trust, this study contributes to the literature by clarifying how sustainability acquires moral meaning in consumers’ brand evaluations. The study demonstrates that a brand’s sustainability image is a multidimensional construct, shaped by consumers’ perceptions of a firm’s ethical and sustainable orientation. As contemporary marketing shifts toward a paradigm in which technology and brand purpose merge, creating social value becomes essential for building strong, sustainable relationships with informed consumers.

A key finding of this study is that a sustainability image serves as a vital source of ethical legitimacy. When perceived as authentic and consistently implemented, it fosters trust and allows consumers to interpret the brand’s actions as morally and socially responsible. Greenwashing or inconsistencies between claims and practice can undermine this trust, highlighting the need for coherence between discourse and action. The path to a credible, sustainable brand image remains challenging. Consumers are increasingly sensitive to changes between promotional claims and actual performance, and behavioural and structural factors can moderate the impact of sustainability initiatives on consumer behaviour. Consequently, for sustainability to be a genuine source of long-term value, it must not be treated as a superficial marketing trend, but rather as a fundamental strategic posture that ensures consistency between a brand’s discourse and its concrete implementation. Ultimately, sustainability becomes a moral and strategic signal that strengthens ethical legitimacy, competitive positioning, and long-term value.

Looking ahead, the findings open several paths for future research. Further studies could examine how cultural, institutional, and sector-specific contexts shape interpretations of sustainability as an ethical signal, and how these perceptions evolve in response to regulatory changes and societal expectations. In addition, future research may explore the extent to which structural constraints, such as economic pressures or consumption norms, limit the translation of ethical sustainability perceptions into concrete behavioural outcomes. Addressing these dimensions would contribute to a deeper understanding of the conditions under which sustainability can move beyond symbolic legitimacy and generate substantive ethical and societal impact.

References