
This has nothing to do with the dolphin tour, but I wanted to chime in anyway since I've had similar experiences.
I've had some great experiences through Groupon/LivingSocial and some bad ones. The one thing that continues to boggle my mind is that the businesses using these services seem annoyed when a customer comes in with a groupon!
I bought a Groupon for a local restaurant that worked out to something like $20 off the meal. When I presented it to the waiter before ordering, he came back with the manager who was completely irate. He said he can't possibly accept that, there's no way they can make money if he gives everyone $20 off, he told Groupon to take it down, blah blah blah. I wanted to leave and not give this guy a cent of my money, but DH wanted to stay so we ended up paying full price for the meal. I should mention that we were the only people in the restaurant and it closed not that long after. Groupon did give me a credit for what I paid for the voucher.
I had a similar, but less extreme situation with Living Social. Every summer a kayak rental place offers 2-for-1 rental offer through LS. The first year 6 of us did it and had a blast, so I bought the voucher again last summer. When I called to make a reservation, I mentioned to the owner that I had done the same thing the year before and he got mad at me for not buying directly through him and paying full price! I'm sorry, but as much fun as it was, I wouldn't do it for an extra $50.
I wonder if these business think Groupon will be a great way to get new customers in, but then they end up in a contract they can't get out of and quickly realize they just lose money. They all seem so bitter!