Dave Meltzer is generally the best source for information on the number of pay-per-view buys the UFC does for each of their events, and this week was no different. Meltzer provided the numbers for the last three PPV's - UFC 147, UFC 148, and UFC 149 in in this week's Wrestling Observer (subscription required):
UFC 147 looks to have done closer to 140,000 buys, which would be the lowest of any PPV since 2005. That’s the Vitor Belfort vs. Rich Franklin show from Belo Horizonte, Brazil. UFC 148 was more than 900,000 but latest estimates have it short of 1 million. We don’t have an update on UFC 149, but the first number we heard was 235,000.
Yes, he meant to type Wanderlei Silva vs. Rich Franklin, not Vitor vs. Ace. Obviously the UFC 147 number is terrible, the worst of the TUF era and even worse than WEC 48 did. It should be said that the show was designed for Brazilians though, and it did great in Brazil. It does set a PPV floor much lower than what it was before though, which can't be a good sign.
As for UFC 148, it has come down below a million which is what I expected. Dana White still doesn't have much to be disappointed about but when you consider the record gate (for Nevada) and the amount of promotion the event got, not doing as well as Rashad Evans vs. Quinton Jackson at UFC 114 shows that business is definitely down.
Finally, 235k for UFC 149 is actually not bad considering the lack of starpower on the card. It turned out to be a terrible event though, which could possibly affect UFC 150 in some way.