There are many variants out there, ie what we have here in Switzerland (buyclub, mostly Geneva) has mandatory drink per person, 5$ minimum, and also usually dis

There are many variants out there, ie what we have here in Switzerland (buyclub, mostly Geneva) has mandatory drink per person, 5$ minimum, and also usually discount is often 40% and not 50%, no cashback. When we use it we always paid quite a bit on top already-paid discount, happily (starters, cakes, drinks, coffee all ads up). Often same places keep reappearing on the offer, so it doesn't seem to be bad deal for them. Deals don't come very frequently, have strict limit on total coupons count (ie 200, 500), how many per user, timeout etc. Another variant of the concept is ie La fourchette (the fork), where you can get similar deals, but they are either permanent deals or stay around for longer, so if you don't have anything specific in mind you just search what is available around. Similar rules for drinks.