As noted by CBS, members currently have to show a membership card when they enter a Costco store. Cards are not transferrable, although the company allows two per household.

But the company has been finding that, particularly in the age of self-checkout, non-members are using the cards of Costco members to do their shopping.

Costco tried to fight that by requiring cards to be scanned at checkout time, but it's experimenting with a new approach.