I think I heard of Ronda Rousy because she was posing for some swimsuit magazine. Not sure who the other people are. Ken Shamrock? Was he MMA or WWE? I can't remember.
I would have to bet that Boxing is much more popular on a world stage than MMA. And given what Pac/Mayweather will draw, I can't imagine MMA is more popular than boxing in the US even though people have been saying boxing is dead for 30 years.