What's with all the MTV Mash Ups?!

I did a search on LimeWire for "Mash Ups".. and there was a HUGE list.

Nirvana and Beyonce - Smells Like Teen Booty
Green Day and Nelly - Country Basket
Nine Inch Nails and 50 Cent - Closer In Da Club
Daft Punk and Eminem - Harder, Better, Faster, Shady
Linkin Park and Britney Spears - Toxic/Faint
Wyclef Jean and Daft Punk
Green Day and Wyclef Jean

There were a bunch others.. I just forget the names.

Most of them that I listened to were pretty good. But, there are too many. WTF made MTV think of this?! Nelly and Green Day!? OMFG GOLDMINE@!!W !@