I've used them multiple times -
The best ones are when you get the discounted ones;
75% of the ones I've purchased were $1.50 for $10 certificate
Works perfectly, just ask the waiter/waitress up front to make sure they still accept them (we haven't been turned down once yet)
ONE MAJOR DISCLAIMER: SecretMethod already mentioned it, but it's very important: check the restrictions on minimum purchase.
We went to this one restaurant where it was "$25 off a $35 purchase"
Well, my wife and I went and it turns out the restaurant was very inexpensive - great food, but cheap. We had to bloat/glutton/overstuff/pig out in order to eat $35 worth of stuff - then, after tax, the total was like $37 - then a tip made it like $43.00 -
Take the $25 certificate away from $43 and you get $18. Factor in the coupon cost (I think we paid $5 for that one) and the total is back up to $23. My point?
We could have eaten there for $12 quite easily. So the coupon made us worse off.
I guess the moral of the story is: if you purchase the coupons that have a $35 (or higher) minimum purchase requirement, make sure you take 4 people to the restaurant
Otherwise, a great deal. The $1.50 for $10 credit is an amazing deal.