Exploring the endorsement effectiveness of professional athletes vs. fitness influencers on Instagram.

A well-liked and frequently used method for practitioners to promote their products is to employ celebrity endorsements, which are advertisements together with actors, supermodels or athletes. Furthermore, marketers increasingly hire so-called ‘social media influencers’ to endorse the brand and their products on different social media platforms and use these influencers as the face for their ad campaigns. According to existing literature, it is a major challenge for marketing managers to select a suitable endorser and hence, there is a great demand for a deeper theoretical insight into what endorser type, i.e., celebrity or influencer, is more effective in the concept of advertising on social media. However, current literature has paid little attention combining these two approaches of influencer and celebrity endorsements and investigating their relative efficacy as a marketing tool.
Therefore, this study explores the endorsement effectiveness of fitness influencers versus mainstream sports celebrities. With the help of a 2 x 2 online experiment and a subsequent questionnaire this research aims to provide further insights of the relation between two different endorser types and their relative endorsement effectiveness and if this relationship is affected of the product-endorser fit. Furthermore, the study investigates if this relation is mediated by credibility, identification and commercialization.
For the empirical data analysis, a total of 219 responses of generation X, Y and Z were valid. Results revealed that professional athletes are perceived as more credible as consumers trust them more and perceive them more attractive and knowledgeable compared to fitness influencer. Moreover, credibility and identification mediate the relationship between endorser type and endorsement effectiveness. Further, results showed that commercialization has a significant negative impact on attitude towards the brand. In contrast to these findings, results did not indicate a significant difference between the two endorser types on endorsement effectiveness. Lastly, product-endorser fit is equally important for influencers and celebrities in regard of their efficacy.