These things have been out ever since, but their use is very limited. My employer uses one, and you can pay at the cafeteria or the inhouse vending machines with it. My university had one for the copy machines. I guess, after years of use, I left my alma mater leaving some pfennigs on it, maybe even a deutschmark, but I doubt it wrecked the economy.

Their use is limited to what I would call a "close circle", exactly for the reason that you can't use it elsewhere. And "elswehere" always will be a much bigger part of the economy than your local laundomat.