When you enter the octagon on the highest level with a skilled opponent across from you, no additional motivation is needed than trying not to get severely injured or humiliated, but Ultimate Fighting Championship (online betting) still managed to do something amazing by adding performance bonuses to events.
Fighters already earn quite a bit of money, but adding that sensation that a single strike can earn you an additional $50,000 or more, that you can basically be crowned the champion of the night, giving you a kind of supremacy over the other fighters without having to fight them, surely guarantees for an even bigger adrenaline surge.