From MMAWeekly.com:

According to Kahl 4.3 million people tuned into the broadcast throughout the course of the evening.
...
The ratings for men and women in the 18-34 and 18-49 categories were down 11 percent and four percent, respectively, from EliteXC’s CBS debut in May, the last card to feature stars Kimbo Slice and Gina Carano.

Kahl stressed the ratings were a good sign of improvement after a lackluster showing at the second CBS-televised EliteXC card in July, particularly impressive considering the college football and baseball playoffs they aired against.
...
Kahl said there was no reason CBS wouldn’t broadcast a fourth EliteXC show.

Kelly Kahl, the person referenced in the article is the Senior Executive Vice President for CBS Primetime Television, so it's understandable that he'd be optimistic about the numbers.

However, I tend to think these initial ratings don't paint such a rosy picture. For one thing, the numbers in key demographics are down from EliteXC's initial ratings from its show back in May. And, that's with a main event featuring Kimbo Slice and a card also featuring the "face of women's MMA", Gina Carano.

While some would argue that EliteXC was competing against college football, baseball playoffs, and UFC counter-programming this time around, the point is that apparently EliteXC's first two shows created no new MMA fans and in fact had difficulty retaining the viewers from those shows.

The main issue is, why is this the case? Does MMA actually have limited mainstream appeal? Or do mainstream fans recognize EliteXC as the inferior product that it is when compared to the sport's #1 promotion, the UFC?

And for EliteXC, the question is, can the promotion succeed without both Kimbo Slice and Gina Carano on the card? The second show flopped in the ratings without either fighter on the card. And, with Slice having been exposed two fights in a row now and his mystique all but evaporated, will he continue to remain a big draw? Is it enough to be scary-looking and look the part of an MMA fighter or do mainstream fans crave skills as well?

Only time will tell whether CBS' experiment with EliteXC worked and whether MMA as a sport benefited from the trial. However, I've seen nothing in the first three shows that changes my opinion that it would have benefited the sport much more had network TV's first primetime promotion been the UFC rather than EliteXC.