They've sold over 1.4 million certs on eBay.
http://feedback.ebay.com/ws1/eBayISA...restaurant.com
I think you can say that a significant majority of the people are happy with the results. You might want to advise the server that you're going to use that before ordering, just to make sure there isn't going to be a problem later. If you do have a problem, you can contact restaurant.com and they should be able to take care of it for you.