Bummed.
I first bought some certificates in April, 2010 and could honestly say that I've only "used" them twice. Each time, worked great. But, I missed the fine print on some purchases, so I contacted them back in 2010 and they "gladly" gave me a credit, which they said would never expire. Yes, I have the emails as proof.
My $175 credit has been on their books for the last 5 years because I just can't find anything I want to use it on. There are tons of limitations on many of the restaurants that are listed.
One restaurant told me that they kept telling restaurants.com that they wanted to cancel their offer, (but it still appears) so they wouldn't/couldn't honor my certificate.
I emailed them three times to try to receive my $175 back. After all, they've had it for 5 years! But... no response to date. So I'm giving it one more try to get a response from them and mailing them a copy of my email to their US mailing address.
Then, I Googled "is restaurants.com legit"... and got here. Boo. Guess that was an expensive dinner we had back in 2010. Not happy.