I did, they were active before Facebook had games, then when cell phone Apps dominated the market it all changed. Microsoft has similar services, if they still do. Microsoft shifted their focus completely towards developers recently and they will benefit from it, not sure what I would do if I were Yahoo other than close down anything not worth it's dollar.
Right. I knew about Yahoo BOSS, but since Yahoo just resells Bing, it was kind of pointless for Yahoo to still have a search API. Bing has a similar API, so if you need this, there's a migration path.[1]