Originally Posted by IAN-UK

I can sail more or less serenely through (small scale) taxi overcharging. But the DCC scam sends me into a barely-controlled fury at hotel check-outs, and has initiated long-running email exchanges over just a few dollars. If one more agent tries to explain it is a service much-welcomed by their clients ...

I've always assumed the merchant gets a kick-back from the bank in this scam. It's (pretty much) small beer on an individual basis, but mounts up to a tidy sum across the Tesco network - or on the scale it is employed to scam hotel guests.