> Smells like an FCC regulation waiting to happen

I don't see a problem. Users want influencers backed by brands. Brands want influencers with lots of users.

Unless the influencer falsely represents their sponsorship history to a brand, this "hack" doesn't hurt anyone. The worst-off party are users. They follow someone they think is shilling products but is actually shilling themselves. Given this is Instagram, I don't see that as a huge problem.