*sigh*
Let's think about this really hard. Chaell Sonnen lost his last what, 3 fights? Yet he still sells like crazy. Lesnar is a monster, I respect him as a former wrestler myself, but not that great in UFC. Yet, he sells well on PPVs. I'll let you think about it, and I'll give the answer below
*pssssst!* THEY TALK SHIT! When people talk shit, like Mayweather and Sonnen and Lesnar, people will pay money to see them get their ass knocked around! (I'm hoping you reached this conclusion w/out cheating and looking at this answer)