Groupon (GRPN) CEO Andrew Mason goes after his company's doubters in a long memo to employees....

|By:, SA News Editor

Groupon (GRPN) CEO Andrew Mason goes after his company's doubters in a long memo to employees. Mason bashes daily deals competitors such as LivingSocial and Google Offers (GOOG), defends a controversial accounting tactic that invited SEC scrutiny, and dismisses claims the company is short on cash. Groupon filed for an IPO in June.