Never used Salon myself, but I've also seen this a lot. I assume a lot of these organisations pull in some third-party credit card processing, then when asked "do you want high security and low fraud?" they answer "Yeah of course"

Then the credit card processor asks for card details, full address, phone number, captcha, browser fingerprinting, IP address reputation, validate the payment in your bank's app, reject foreign cards, reject prepaid cards, and so on.

Then a customer like me who is literally at the checkout trying to give them money isn't allowed to.

And they're selling digital goods - pixels are free, a non-paying customer doesn't cost them anything!