I used them twice, the first was great! The web capture gave me potential lead feedback. The second unfortunately didn't include the web capture feature (unknown to me). I wondered why I didn't get any feedback, until I went to a client's house and saw the postcard didn't have the web info. When I asked Corefact they said the template I chose didn't have the web capture. It is not easy to find which ones do and don't so be very careful to choose the web capture option. Otherwise, it just another postcard mailer!
ps- Their customer service isn't that great, so if you know of any other providers of these please let me know.