Googling around a little bit it actually seems like they have a lot of their largest customers in their US. Apparently Whole Foods, Walmart a bunch of other retailers and several American government institutions like Fema and several city administrations.
Wouldn't surprise me if the US is actually their largest market.
Continental Europe was by far their largest market just a couple years ago. North American expansion was always a matter of discussion (if not investment) but it has only really picked up steam in the last year or so.
I have Very fond memories of KDE ~3 running on SuSE 8.1ish in the early 2000s. My XFCE setup today is far cleaner and more efficient, but it doesn't give me the same sense of satisfaction.