Regulatory filings are special. Also, in Groupon's case, amortization of marketing / customer acquisition costs depends on a particular model of customer reten

Regulatory filings are special. Also, in Groupon's case, amortization of marketing / customer acquisition costs depends on a particular model of customer retention (which is part of the reason that for regulatory purposes it has to be fully accounted for in Year 1). It's a lot more likely for someone to become a lifelong Amazon customer than a lifelong Groupon customer after their first purchase. Also, Groupon doesn't really have "R&D" of the kind Amazon does - robot warehouses, elastic computing platforms, & logistics systems are both expensive to develop & very valuable.