Yes, exactly. US. Every millennial has Gmail, idk what GenZ does, probably also Gmail. GenX and Boomers probably split between Gmail, Yahoo, iCloud, and a few AOLs - and that covers probably 95% of Americans.

It was almost embarrassing for me, I have to admit — especially times when I’d been clever about it and set up, say, searsaccount@myname.com as a forwarder, and the cashier at Sears needed my email address. They once asked me oh, do you work for Sears?

I feel like the US have a culture of big chains like that. You want an email? GMail. You want mexican food? Chipotle. etc. I don't mean that as a criticism, but there seems to be a cultural thing.

In most parts of the world, you don't almost exclusively chains of restaurants, and people don't expect that. Just like it's normal to have someone suggest a restaurant you have never heard about, it's normal to have someone use an email provider you've never heard about.

Or maybe that's completely unrelated, I don't know :-).