They've recently started up a business selling MP3 files that you play alongside movies. Since they don't have to pay for broadcasting rights, they make fun of more popular movies (compared to the B-movies on MST3k) , like X-Men, The Matrix, 5th Element, Halloween, Star Wars Episode 1, The Grudge, and Britney Spears' Crossroads.
I thought any MST3K fans here would enjoy knowing this site exists:
http://rifftrax.com
I've bought a few, and they were
*∞