Igniting interaction: decoding the impact of address formality on consumer brand engagement in online service agents

Purpose As brands increasingly leverage online service agents for consumer interactions, optimal engagement initiation strategies—particularly address forms that elicit positive responses—remain underexplored. This study examines how service agents' address type (formal vs. informal) impacts consumer’ brand engagement, while investigating underlying cognitive-affective mechanisms and testing critical boundary conditions. Design/methodology/approach An exploratory analysis identifies prevalent address terms used by 245 Chinese e-commerce brands. Three scenario-based experiments (N = 1,140) tested the hypothesis. Findings Informal address (vs. formal) increases consumer brand engagement. This effect is independently and sequentially mediated by psychological distance and perceived warmth. Brand positioning moderates the relationship: informal address significantly boosts engagement for mass-market brands, but not for high-end brands. Originality/value This study refines linguistic style research by shifting focus from macro-level styles to micro-level nominal address formality in e-commerce. It advances digital interactive marketing literature and provides practical guidance for tailoring online service agents' language.