The chairman and cofounder of the beleaguered company defends daily deals, opens up about its problems, and tries to redefine the service as a next-generation Costco.

"Seems like Andrew has too much swag for a public company. They need to find more of a 'boring loser' type," and other notes on Mason's farewell memo.

One month ago, I interviewed then-Groupon CEO Andrew Mason for a forthcoming Fast Company feature on the future of Groupon. His performance--at turns, defensive, weary, combative, and naïve--foreshadowed his firing on Thursday.

"My biggest regrets are the moments that I let a lack of data override my intuition on what’s best for our customers."