I'll just let the staggering numbers below speak for themselves.
From Dave Meltzer's WrestlingObserver.com newsletter:
UFC did about 5,225,000 in domestic buys with a total gross revenue for PPV events of $222,766,000. The 10 live PPV shows did over $40 million. Their PPV number of $222 million is a record, beating boxings record year in 1999 of $200 million. The UFC PPV revenue was up over 700 percent over 2005.
I think it's safe to say that 2006 was a banner year for Zuffa and the UFC in terms of profit and growth.
Thanks again to UFCmania reader "Nate" for sharing the news.