> but it would invite a secondary market for these cards There are already markets for fake IDs, so unless you're suggesting that small local restaurants purch

> but it would invite a secondary market for these cards There are already markets for fake IDs, so unless you're suggesting that small local restaurants purchase scanners to confirm the authenticity of each ID, it would be relatively easy to circumvent this check too. (Some states require IDs to be scanned for selling alcohol, but many, e.g. in Oregon, do not, and the only check is some employee looking at a card in their hands for a couple of seconds) > Plus having special cards feels corporate Not at all. Plenty of local restaurants in my are (Portland, OR) have rewards cards, where you get stamps and a free meal after some amount of stamps.