Nice‐to‐Have or Must‐Have? Revisiting the Corporate Sustainability–Customer Loyalty Relationship Across Generations

ABSTRACT This study revisits the relationship between environmental and social sustainability and customer loyalty, integrating both sufficiency and necessity theoretical perspectives within a generational framework. It examines whether generational differences moderate these relationships and whether these sustainability dimensions act not only as sufficient but also necessary conditions for loyalty formation. A cross‐sectional survey was conducted among 1263 retail banking customers from Generations X and Y. Results reveal that environmental and social sustainability indirectly boost customer loyalty by increasing customer–company identification and satisfaction. However, environmental sustainability has a stronger impact on loyalty among Generation Y, while social sustainability is more influential for Generation X. Moreover, both sustainability dimensions are necessary for loyalty formation among Generation Y, whereas only social sustainability is necessary for Generation X. This research extends the sustainability–loyalty literature by applying a dual sufficiency–necessity framework and by introducing a generational lens to assess the influence of perceived corporate sustainability.