At www.divx.com you can now download version 5.0 of their software. There are, in effect, two versions - the Basic and the Pro. Basic is free. Pro costs $30, unless you're willing to put ad/spyware on your system, in which case it's free.
Now, think about their target population for a second.
DivX format is primary used for making illegal copies of video.
Say it again: ILLEGAL COPIES.
How many copies of DivX pro do they honestly think they can sell to this crowd?