Groupon's downfall, if it ever does happen, will likely be traced to its decision to go public. Ever since its first S-1 filing, in which it was roundly mocked for constructing a performance metric that eliminated the costs of its marketing, the company has been battling perception that its model is not sustainable.

The Securities and Exchange Commission just threw more fuel on the fiery debate, releasing comment letters it sent to the company leading up to its November IPO. These question many of the claims the company made, some relating to its advertising and marketing models, others to executives’ statements during the quiet period.

Their release was a not-so-welcome reminder to the industry the daily deal market is seen as precarious by many.

Still, there is little sign that it will head into a tailspin decline any time soon—but clearly changes are coming to the model.

Death of the Groupon Clones

Tippr is predicting that many of the Groupon clones will close shop next year (via Xconomy). "Data from the industry aggregator Yipit pegs the number of failed deal sites this year at more than 170, and Tippr predicts that more than 200 will go down in flames in just the first half of 2012,” it said.

Optimistic Growth Path

Others see strong growth in the model—a projection that doesn’t necessarily rule out consolidation. US consumer spending on deals (including daily deals, instant deals and flash sales) will grow from $873 million in 2010 to $4.2 billion in 2015, representing a 36.7% compound annual growth rate (CAGR), according to BIA/Kelsey.

Deals spend is expected to reach $1.97 billion this year, about 2.25 times the 2010 total.  In March 2011, BIA/Kelsey had predicted 2015 deals spending at $3.9 billion, with a 35.1% CAGR. This revised forecast increased the 2015 total by almost 8%. However, revenues for 2011 have been revised upward significantly, by about 64%, from the $1.2 billion originally estimated in March.