Is it really cheaper or free for non-Europeans? (
http://exchangestudentworld.com/student/costs/) Can it be easily done without going through an exchange service? Anyway, some other possible factors for why more Americans don't do it: not many European schools actually wanting them for various reasons (such as academic performance (or as sibling notes there may be an entrance exam), they're full enough with the locals, or would rather have non-American foreign exchange students), most Americans don't know a foreign language very well (and those that do are most likely to know only Spanish), most Americans stay in the same state of their birth, and lots of college students like being able to visit friends and family from their original location and that's a lot more difficult with an ocean in the way -- flights are expensive.