OMGPOP was smart to do this deal. They really had no choice. It seems really difficult to come up with new games. If they didn't do the deal, Zynga would have cloned the app and introduced it to their huge network of "_____ with friends" players for free and OMGPOP would have lost market share and revenue.
It actually wasn't single founder when YC funded them, Dan Albritton was the other founder. Really nice to work with them back in the day.