I was suggesting the possibility of different coupon services marketing themselves to different segments of the populace; the most common characterization (as f

I was suggesting the possibility of different coupon services marketing themselves to different segments of the populace; the most common characterization (as far as I can tell) of people who use Groupon is as cheap or stingy, so a service which was able to promote a view of its subscribers as more affluent or using the coupons as a low-risk way of trying something (as opposed to just shopping for deals) would be better placed to market to businesses. However, you're completely right that clients would go with whichever service offers the best value and best range of coupons, and that scale offers an advantage there. I would add that it is highly unlikely that subscribers would only subscribe to a single service. With the marginal cost of subscribing being so low (just signing up with an email and then looking at the deals when they show up, as I understand it), the increased variety of coupons would almost certainly sway the majority of subscribers. At that point, it would become a fight over which service can find businesses offering the cheapest or most desirable deal, in which scale gives the advantage.