I went along to one of these in the Carribean - it was actually really interesting, as we had a good nosey around the property in question, a meal, and left with hats, t-shirts, bottles of rum, and, the real reason we had gone, a full day sailing trip for 4, wortha couple of hundred dollars per person. Whole thing took maybe 90 minutes - not a bad return for a meal we would have eaten somewhere anyway, and a bit of a nosey around a resort!