TIL British retail establishments say "thank you for your custom."

(at least when they're being formal or fripperish).

Makes sense, of course, given "customer" and "customs duty" and so on. Just hadn't thought about it.

It it fairly commonplace? Out of fashion? I've never before had it said to me in person in London nor conveyed in an online purchase thank-you.

On a related note, apparently American retail establishments have now taken to have their sidewalk barker say, or their signage declare, "you're welcome" as a phrase of invitation to come inside. That's very weird to me.