I just played golf with a big influencer (>5Mn on IG) who said brand sponsorships are still the main way he makes money.

How do you price an influencer? It is an interesting question. Two ideas: (1) if you have access to more conversion data you can generate more accurate predictions and arbitrage better. so centralized players that sit on proprietary data have a structural advantage (2) if you are a influencer with bad engagement, you hate this. if you are a influencer with good engagement, you like this. there is a natural incentive for high engagement influencers to share and publicize their conversion rates

I suspect this is a very inefficient market and current pricing models are not sophisticated