Business cards come in all shapes and sizes. The "standard" business card is 90mm wide x 55mm high, printed full colour on one side or two sides on a quality cardboard like 310, 350 or 420 gsm artboard, and usually with a gloss or matt laminate for good looks and long life.
Now consider a plastic business card, size 86mm wide x 54mm high, printed full colour on two sides of quality gloss PVC plastic. These classy looking cards never wear out, never look tired, don't fold or crease and will always fit in your wallet.
Sure the cost of plastic cards is slightly more than cardboard cards but the benefits, in my opinion, outweigh the costs. Plus a plastic card sets you apart from everyone else and helps you make a statement that will likely get you remembered when everyone else with a "standard" business card has been forgotten.