this, everyone saying you get nothing is wrong. when you get your results back it will tell you if you qualify for a national merit scholarship, which you can receive if you end up doing very well on the sat in addition to having good grades. i qualified and kicked ass on the sat, but my grades weren't anywhere near high enough for me to actually be competitive the scholarship.
even qualifying for national merit is pretty dope, as people said above prepare to get fucking bombarded with letters from about a million schools you probably don't want to attend -- i'm pretty sure my parents still get postcards from some jewish university. not only am i not jewish, i took the sat two years ago.