Andrew Mason out at Groupon
Too bad for Mason.  IMHO they should have sold to Google when they had the chance.  There are many folks who applauded the decision to decline the offer.  Build for the long-term, they said.  In general I agree with that sentiment.  But when you have a $6B offer on the table, you gotta put the kool-aid aside and be very objective about the future prospects for your company.