For longtime mixed martial arts fans, UFC 137: "Penn vs. Diaz" featured a "must-see" main event, pitting former welterweight champions B.J. Penn and Nick Diaz in a 170-pound contender's bout for a crack at Georges St. Pierre in early 2012.
For the general public? Not so much.
That's because UFC 137 drew an estimated 280,000 pay-per-view buys back on Oct. 29, 2011, for the event held at the Mandalay Bay Events Center in Las Vegas, Nevada.
Those numbers are courtesy of Dave Meltzer (via Bloody Elbow):
The latest PPV estimates we’ve gotten from cable sources are about 225,000 buys for UFC 136 (Maynard vs. Edgar III) and 280,000 for UFC 137 (Diaz vs. Penn). I should also mention that sources close to UFC claim the 136 number is considerably higher and 137 is identical to our estimates, and that both numbers are likely to end up in the same ballpark.
Why so low? MMA Payout examined the troubled fight card prior to the "Sin City" event:
The top of this card was hurt first by Diaz’s no-shows, the card reshuffle and GSP’s injury. The UFC first touted UFC 137 as being Champion vs. Champion. Despite the removal of GSP from the main event, the UFC indicated that the show was a sell-out. After GSP’s injury, the card took a big star power hit despite BJ Penn in the main event. The co-main event featured mid-card level talent (Nelson, Mitrione, Kongo and Cro-Cop). Cro-Cop is past his prime while the other 3 are not top of the card caliber. It would be hard to foresee the buys for this card exceeding 350K.
It can be difficult to see outside the inner circle when talking about fan appeal. For the vets, this was a attractive card. For the casual fan, there wasn't enough star power to convince them to open their wallets.
Which is probably why it was only separated from UFC 136, headlined by Frankie Edgar vs. Gray Maynard III, by 75k buyers.