Colleges could buy bundles of students at auction instead of processing individual applications.
A single company (possibly Common Application) could bundle students into securities based on their GPA, SAT score, and ability to pay for college. The company would then rate rate the potential revenue
of these securities the same way people rate any other security: AAA, AA+, AA, AA-, A+, A, A-, BBB+, etc. The academic side would be rated similarly. So a security could be AAA on potential revenue and AA- for academics.
The number of students per security would vary, but would probably be more than 1,000. The main colleges interested would be large state schools and large research schools. They'd be interested because it would save their admissions offices a lot of time and money. Think of all the admissions officers they could fire.
Liberal arts schools probably wouldn't be interested. However, smaller boutique firms could try to cater to them by taking other factors into account, like personality or writing ability. Smaller bundling companies would operate like normal admissions offices do today. The current system is inefficient because students have to be evaluated by every single college they apply to.
When colleges buy a security at auction, the money would be distributed evenly amongst the students in the security. The company charges a fee. In effect, students trade their academic standing and the ability to choose a college for cold, hard cash.