A "land grab" strategy implies there is a means to lock out competition, and a strategy to defend and retain the land that is grabbed. So, one has to ask, what is Groupon's retention strategy for all this wallet-share they are grabbing?
Vendors and customers who are of the mindset to avail themselves of a Groupon-like service are driven by the value of the deals. There is no inherent loyalty to the voucher provider, or automatic lock-in of mindshare. If vendors and consumers can get a better deal from someone else, they will.
So, while Groupon, LivingSocial and the rest may currently enjoy decent margins, what prevents them from being locked into a race-to-the-bottom of razor thin margins as the markets saturate? To my mind, having the largest list of emails to spam with targeted offers is not a sufficient defense against this. It just slows the attrition.
So, then the question is, if there is nothing that prevents a race-to-the-bottom, aren't the companies that maintain the highest operational efficiencies (and profitability) - not the ones that grab fastest the most of the ultimately indefensible lands - going to be the ones that prevail, in the end?
And, let's not forget, this land grab strategy is/will be failure unless Groupon can actually raise the capital required to actually stay in operations and see through to fruition.