A year ago I was showing a variety of the products I sell (not cards, but bags/boxes/folios etc) at a rubber stamping convention. I was on a tight budget. I used white cardboard display boards (a few bucks) that I pick up at office supply stores for my kiddos science fair projects. I layed out the boards and figured out what I wanted to display on each. I stamped on the dead white space to add some interest to it (I included my logo there as well). I used velcro dots to hold the pieces in place, since I thought I might re-use the displays and samples at a later time. They also sell low tack Zots/Glue dots at some office supply stores (I've only ever seen the permanent glue dots at scrapbook stores). Low tack ones are great for displays because you could easily remove the cards to use/sell them later. I wouldn't, however, let customers remove the cards from the displays--the display would move around. HTH
Annette
http://stamponthis.com