There have been many pretenders rise up to challenge the UFC's dominance of the mixed martial arts business—nearly all have failed.
The three most notable failures in recent memory are the IFL, Affliction and EliteXC.
The IFL was a team-based MMA promotion founded by a magazine guy and a real-estate developer. There was tons of hype around them because they had a deal with FOX Sports Net and a unique pay structure that payed fighters actual salaries rather than just fight purses.
They didn't last, in part because of their absurd concept (nobody cares about the New York Pitbulls or the Quad City Silverbacks) and in part because they became publicly traded, turning the reins over to shareholders and a board of directors that new nothing of the fight business. They shut their doors in 2008.
Affliction was a shorter story. The much-mocked clothing brand decided to start their own MMA promotion, with Russian heavyweight Fedor Emelianenko as their marquee star.
They put on two events that were watched only by hardcore fans. Their third show—supposed to be headlined by Emelianenko vs. Josh Barnett—fell apart when Barnett could not obtain a fight license. The promotion folded, although the Emeliananeko-Barnett debacle was just the straw that broke the camel's back. Affliction wasn't a sustainable promotion; they were overpaying their fighters relative to how many PPVs they were selling.
EliteXC was possibly the greatest threat to the UFC since the promotion—lead by boxing promoter Gary Shaw and his son Jared Shaw (a.k.a. $kala)—actually earned a spot on broadcast television. They had a prime time slot on CBS!
But EliteXC, too, wasn't sustainable. Fighters were overpaid (Tank Abbott earning 126k? He probably would've fought for a six pack or two) and the promotion was built on a weak foundation—YouTube brawler Kimbo Slice.
Kimbo was their only star. When he lost to Seth Petruzelli (a pink-haired man who wasn't nearly as impressive a physical specimen as Kimbo), the game was up, especially since Petruzelli hinted after the fight that EliteXC officials wanted him to stand with Kimbo, prompting an investigation to be launched against EliteXC.
There were dejected Pride fans rooting for each one of these promotions to destroy the UFC, yet the love of these woebegone cretins couldn't keep these organizations running.
They lacked knowledge of the MMA business; these fools and their money were soon parted. And to have thought that they actually could've beaten the UFC was laughable. The UFC is MMA the same way a kleenex is a tissue and a band-aid is an adhesive strip.