I understand what you are trying to say but I’m not sure how meaningful that 60% is without more data. Like is 60% USA unusual for a Kickstarter? What about for Sanderson’s typical sales?

Like a quick search of where English is spoken shows that about 67% of people who speak English as their primary language live in the USA. It drops to 30% for total English speakers (primary and secondary) but it wouldn’t be surprising if people speaking English as a secondary language wanted to wait for a hard copy in their primary language.

So yeah, without more context I’m not sure that 60% USA is that surprising. Unless Sanderson has a huge following of people who like their books in his native language instead of their own…. That falls in line with the percentage of the population with that as their primary language. It’s an USA owned website hosting an USA author’s book in the language that the USA has the most primary speakers of said language. I’m not sure shipping is the reason the USA is the largest percentage of backers despite Sanderson’s worldwide appeal.