I agree. Personally, I'm not sure my retention on things I've tried has been great for the businesses doing the offering. Things seem to end up a few different ways:
1) I love what they're offering, but I want to do their thing somewhere else, so another business gets the benefit.
2) I don't like what they're offering, oh well, gave it a try
3) I like what they're offering and they're in the right place for me to continue doing business with them
#1 is the hardest for businesses, and I admit to engaging in a fair amount of "Groupon tourism", where I'll go a little out of my way to try something just because I got it for cheap on Groupon.
For #2, sometimes there's a reason why places aren't doing well and turn to Groupon to try to boost sales, sometimes it's just a bad fit for me as a consumer. For example, I just used a Groupon for a local new Mexican place in my area. Turns out the reason their gorgeous restaurant is mostly empty is because the food sucks. There's a Mexican place down the road from them with low budget hand-made booths that's exploding with customers, the difference is that their food is good.
I'd say I probably stick with less than 10% of the new places I find through Groupon. I'd probably be willing to pay more to try new things...but not a whole lot more. As a consumer I have to change my basic behavior patterns and maybe travel out of my way to try something new, I feel like I'm meeting the place halfway. Sometimes I have to travel someplace I've never been before, and after getting there I'll know if it's reasonable to continue coming out there. The horse lesson I took I enjoyed, but it's also an hour of hard driving to get there, while I live right on the edge of plentiful horse country. Now I know I had fun taking a lesson, I might give a go at one of the local places, but I'll probably not return to the place I used the Groupon with.
There's also places, like a zipline center I Grouponed at. It was cool, I'll return. But it's not like it's an every week kind of place. So I think businesses also have to consider their model. I wouldn't have tried it without the Groupon, but it acted more like an advertisement would.
I also went to a high-speed gokart center on a Groupon. Turns out they already have lots of business, but it's all dedicated racers who knew what they were doing. When I went there I had to sit through a half hour of safety training videos, and when I got on the track it was terrifying because everybody else was hardcore and very aggressive. It could have been fun if everybody wasn't taking it so seriously, or they bundled all the Grouponers into a beginner league or something. So I don't think it worked as an expansion of their basic business.
I think business issues with Groupon are more complicated than people give credit for.