Widely eaten in the Netherlands (though not on its own - usually on bread, and never with jelly). Many people swear by the main brand Calvé, although peanut-only single-ingredient peanut butter has gained serious traction in the past few years.

not really that much, just a slightly exotic item like say maple syrup

I don't think ive ever eaten it by itself, but I can confirm that I've had it on sandwiches in Australia, in Satay, (Golden tofu/chicken) and a peanut stew (African iirc).

Satay sauce and peanut stew are different from peanut butter, though.

I'm Italian and I like it, although I ate it for the first time when I was a PhD student in the UK. In Italy it's not always easy to find.

It's fairly common here in Germany.