I spoke with the CEO of a company that aggregates a very large percentage of the daily deal sites. They have several hundred they currently follow. Two things which may be salient. First, the CEO claimed that the smaller deal sites were all desperate to be aggregated, as building their list has proven to be far more expensive than they expected. Second, the aggregator is seeing a 30% annual turnover in the deal site population. That is, approximately 1/3rd of deal sites go under annually and are replaced by a like number of newly launched companies.
I interpret this as evidence that the lion's share of the market is likely to go to a few large players like Groupon, Living Social, Facebook, etc. It's been 2.5 years since Groupon launched. If smaller players were going to successfully carve up this market, wouldn't we see signs of that happening by now?