As has been discussed here recently, TNA's last few PPVs have drawn around 8,000 buys each, which is beyond pathetic and even lower than what the early pre-taped ROH PPVs drew.
It gets worse.
In the newest Wrestling Observer Newsletter, Dave Meltzer analyzed the Boston Globe story about Dana White. In this piece, he mentioned that during UFC's dark ages, they drew 14,000-19,000 buys per event. This was when they had no TV outlet and their shows were only available on DirecTV (which was much less of a powerhouse at the time), Primestar (Which was dying and sold to/folded into DirecTV in 1999), and a handful of small cable systems, making them available to about 25% of the PPV market. TNA has a weekly TV show seen by a million people and 100% PPV clearance.
So...yeah. There you have it.