It would be in addition to guaranteed money.
That's an interesting idea from Abom. Having incentive to promote yourself, your team and the league could butter both sides of the bread. Now there will be guys who just aren't that popular, ugly, aren't big social media guys etc. But it's a dog eat dog world where only the strong survive.
There would also be an influx of middle aged dudes crying about what d-bags these guys must be to take selfies and promote themselves on Instagram because they're jealous of the chicks they bang and the cars they drive.