Andrew Mason is out as CEO at Groupon, but he’s not doing it very quietly. His farewell letter has been so popular that it crashed the site it was posted on. It’s a funny concept to start with – posting a private farewell letter publicly because “it would probably get leaked anyway,” but all in all, he appears to take the end of his tenure with grace and humor. He takes the blame for Groupon’s problems, acknowledges that he’s been fired, and wishes his employees luck.