I've heard the same advice - put something useful on the back of your biz card so people have a reason to keep it. Lately, I've heard several people mention using the back for listing the url to your social media accounts - Facebook, Twitter, LinkedIn, etc. This give people your info but keeps the front of the card from being so cluttered.

Looking forward to other ideas for using the back of biz cards!

__________________
Gladys Strickland
GS Business Resources