From SeatGeek the ticket search engine that helps fans quickly and easily find the best price for events:

It's clear looking at how quickly UFC 120 sold out, and the addition of more seats that demand is very high. To U.S. fans, UFC 120 might not be a blockbuster event, but for U.K. fans the event is featuring two big English stars (Bisping and Hardy.)
Here are the stats:

• It is interesting to note that tickets are even selling in the US for a MMA event in London, fans are obviously making the trip across the Atlantic
• This demand speculation is supported by the fact that the event sold-out quickly at pricing levels ranging between roughly $80 and over $400 USD on the primary ticket market
• In addition, a scan of of the secondary ticket market in the UK shows average listings prices at roughly $400 USD
• Excluding fees, the pricing tiers on the primary market are as follows: £50.00, £75.00, £100.00, £125.00, £175.00 and  £250.00
• Even though more tickets were issued for UFC 120 at The O2 in London, the cheapest available on the primary market are at the £100.00 price level
• Michael Bisping and Dan Hardy are second tier fighters, but they are both English fighters, and by saving them both to fight on a UK card, the UFC has gotten the absolute most value out of these fighters and this card as a whole

It's very good news for the UFC's UK offices that this event has fared so well with European ticket buyers because there is very little prospect of getting bigger fights in the UK. MMA Junkie talks to UFC UK President Marshall Zelaznik:

"Obviously, championship fights for the most part are elevated to the pay-per-view cards. The pay-per-view cards over here, because of the time change, make it a bit of a challenge in the U.S. to see the impact you're hoping to see from the championship fights.

"It's a bit of a business decision, but that's not to say we'll never have a pay-per-view here or we'll never have a championship fight here.
...
"You can look at TV ratings, but to have people actually reach into their pocket and buy a ticket, whether it's to the expo or to the fight itself, is really sort of confirmation that we are having an impact here, that the sport is growing here," Zelaznik said. "Interestingly, I didn't announce it, but we have about 25 percent of our tickets coming within London, which means 75 percent are coming from areas to the North, coming from Europe, so people are traveling from all over to spend a weekend with the UFC. I think it says a lot about the growth of the sport."

E. Spencer Kyte points out the international flavor of UFC 120 and its implication for continued international growth of the sport and the promotion:

This weekend at UFC 120, eight different countries are represented amongst the 22 competitors taking part in the festivities Saturday night at the O2 Arena in London. In addition to the eight Brits, this card boasts five Americans, two fighters from France, Canada and Brazil, and one from Korea, Sweden and Bulgaria.

Just as a bunch of young Canadians decided to pick up a basketball when they saw Steve Nash holding up the Maurice Podoloff Trophy back-to-back years, fighters like Georges St-Pierre and Carlos Newton before him served as inspiration to the legions of young martial artists looking to earn a living in the cage.

While countries like the Brazil, Japan and the U.S. have an abundance of MMA athletes for fans and future hopefuls to identify with, as the sport continues to expand and fighters from countries that are not currently as represented emerge, those nations have the potential to become hotbeds of mixed martial arts activity and appreciation.