The College Board has been selling student data to colleges since at least the early 1970’s. My undergrad college bought a small-ish sample list from the Student Search service for the HS class of 1973. That college was so happy with the geographic diversity and access to previously untouched student pools, that the list purchased for the HS class of 1974 was expanded drastically. Fully half of the students who eventually enrolled for my college graduating class of 1978 were from Student Search. We sucked so much money out of the financial aid budget that the college was more cautious in subsequent years. My college room mate and I would never have thought to apply to that place had we not received those personal (signed with a fountain pen no less) letters in the mail.
All that said, the College Board rakes in so much money from this kind of thing these days that honestly, the SAT should be free to take. Better yet, the kids should be able to charge the College Board for the use of their data. 