From Dave Meltzer's Wrestling Observer Newsletter (subscription required):
The total attendance for UFC 108 was a heavily papered 12,377 at the MGM Grand Garden Arena. The place wasn’t sold out, and there was a curtain up over the upper level on one side of the arena, the first time I’ve ever seen curtains used for a major UFC event. Paid was 8,004, with a gate of $1,969,670. It should be noted that a lot of that paid was casino buys, noting that the MGM Grand had purchased a large block of tickets (which is common practice for big UFC events) and were giving two tickets away to anyone who booked a room in the hotel that weekend.
Current trending patterns for UFC 108 are at this point looking like 255,000 to 270,000 buys, which if those numbers end up accurate, would be the lowest for a North American show in several years. But most figured that would be the case given all the injuries changing the lineup and it was a patched up show. Just like it wasn’t wise to overreact to 107, which did so well, same here, because with all the injuries, it was a show that wasn’t going to do well and it was just a question as to where the actual bottom base is right now. I’m not sure how 109 will do. Whether the public buys the two Hall of Famers deal will tell the tale. The advertising for it so far has been good. Obviously Couture’s drawing power isn’t what it once was, but if they can do the same business Couture’s fight with Antonio Rodrigo Nogueira did, then I’d consider it a success.
The UFC has shown tremendous resilience in plugging ahead despite the plague of locusts that have afflicted their fall cards and 3/4 of their champions.
On the other hand, by refusing to consolidate two weak cards into one (say combine UFC 108 and 109) they have now established a new floor for UFC ppvs.
If they don't watch out they will train their loyal fans that not every UFC is worth ordering.
MMA Junkie reported Dana White's more optimistic projections:
"We were looking at (projected PPV buys) and ... our norm is around 500,000, and we think we're going to fall somewhere between (400,000 and 500,000)," White told reporters. "We'll see what happens."
Brent Brookhouse at SBNation commented:
Despite claims by some that Rashad Evans had become a major draw on the heels of his stint as a coach on The Ultimate Fighter and claims by some others that the UFC couldn't dip below 350k buys for any PPV, it looks like that is exactly what we're getting.
The card was just brutally bad in terms of drawing power and while it was an entertaining watch it remains true that the event had no real mainstream appeal.