The OMGPOP guys were evil geniuses. They didn't just sell at the top of the market (Draw Something dropped off sharply in users just a month later), but they sold to Zynga in an all-cash transaction, so they didn't get hit by the $13ish->$3 drop in Zynga's stock at all.
It's been 2.5 years since Facebook acquired Friendfeed. Let's raise a glass for a moment and give thanks that the service is still running. I can't think of another acquired service that has continued on so well in a mothballed state.