Lol - I never put a game on them, so I wouldn't know the correct link. Looking around, I can't find it either!
This old 2003 link claims that Yahoo! gets their games from 3rd party sites, and you have to go through them. But that was ten years ago - which sites do they go through now in 2013?
There seems to be alot of shareware sites, actually, so that might be a separate category in itself.
I actually have an Excel spreadsheet I've been collecting for some time with all the game distributors, news sites, and gaming forums that I could find indexed on it by category. Kinda messy though, and the categories aren't very consistent! This kind of stuff needs to be available in a community updatable way like a wiki, or it gets out of date surprisingly fast.