This is an awesome deal. It's no joke either, as I have purchased several myself and it also worked when family members bought some. There is no gimmick. Restaurant.com is actually selling $25 gift certificates for $1!!
This has been going on for a couple of days, so I'm sure most of the "good" restaurants are already sold out, but you might as well see if there are any gift certificates you or a client could use. I bought some for restaurants that I have never been to as I'm going to use my $1 as a way to venture out.