•Influencer-product congruence affects product attitude and advertising recognition.•Sponsorship disclosure is linked to the calculative motive inference of the influencer.•Sponsorship disclosure affects product attitude through a serial mediation.•Social media users infer multiple alternative motives of the influencer. This study investigates the effects of influencer advertising attributes on consumer responses via multiple motive inference processing. Influencer-product congruence and sponsorship disclosure are manipulated as independent variables. In so doing, this study examines whether social media users infer two types of motives (Affective vs. Calculative) of the influencer derived from perceived congruence (High vs. Low) and sponsorship disclosure (Presence vs. Absence). Results suggest that influencer-product congruence can be used to enhance product attitude and reduce advertising recognition by generating a higher affective motive inference. Sponsorship disclosure can also affect product attitude in a serial mediation of calculative motive inference and advertising recognition. The multiple motive inference model explained the dual processing of influencer advertising by attributing to the prior persuasion knowledge and situational characteristics simultaneously. The findings discussed theoretical and managerial implications on native advertising on social media.