He didn't get shafted; he still owns a very significant portion of the business. He simply didn't take as much out with this round as others may have. He will have his payday, and it will make these others seem like chump change...

How much does Mason own?

According to this NYTimes article, about 7.7% of the Class A shares and 40% of the Class B shares: http://dealbook.nytimes.com/2011/06/02/groupon-c-e-o-to-make...