It makes logical sense though, aside from the whole white folks thing.
Let's say you're performing for a brand that is going to make $100,000 off of an event, you might charge them $10,000. But then you're going to perform at an event that is going to earn $500,000 off of the event, you'd charge them $50,000. Or whatever numbers you wanna throw in there. It's not like Hitman Holla is the only person that does this; I used to promote parties and seminars, and most people are like this. Some guys will charge a flat fee period, but most people will negotiate up and down depending on how much money the promoter is going to earn from the event.