If you ever find a restaurant that won't honor the certificate, contact Restaurant.com and they'll give you credit that you can use toward another certificate. It actually works out nice because even if you bought the unhonored gift certificate with a coupon, you can get the replacement any time of the month. Buying at the beginning of the month has better certificate availability but normally doesn't allow further discounts. They release a set number of certificates for each restaurant each month, and some of the best values and/or most popular locations sell out quickly.