A Model of Influencer Economy

We model an influencer economy in which brand owners and sellers depend on influencers to attract consumers while competing in both influencer and product markets. As technologies governing marketing outreach improve, the equilibrium features non-monotonicities in influencer market concentration, payoffs, and distributional inequality. Influencer heterogeneity and horizontal product differentiation are substitutes; small style differences complement vertical product differentiation while large differences substitute. Moreover, assortative matching between sellers and influencers occur under endogenous influence, with the maximum horizontal differentiation principle recovered in the limit of costless style selection. Meanwhile, the sellers’ bargaining power counteracts the influencers’ tendency to over-invest in influence power and they jointly determine the direction and magnitude of the sub-optimal acquisition. Finally, regulations for balanced seller-influencer matching can encourage seller competition under single dimensional seller-influencer heterogeneity. But uni-directional exclusivity contracts are welfare-improving for sufficiently differentiated products and uncongested influencers’ markets.