Forum Moderators: rogerd
If you just have a database, I'd suggest having a coder create a simple script that would run daily as a cron job. A link to an online card would be simple, and you could periodically change the online card without altering the script in any way. This should be a minimal time project.
I don't know if I am typical, but I rarely use my real birthday when I sign up for a forum or other website (unless there's a real need for the site to have it). Hence, a birthday card arriving on January 1 (the usual default in form drop-down boxes) wouldn't do much for me. On the other hand, I've had many "thank you" notes from community members who received an automated card, so they certainly do some good.