How do colleges decide who to offer free applications to?

Some “top” schools entice some students to apply to their school by offering them a free application.

It somewhat seems random who they offer it to?

Any clues how they target that list…

Low income students, URM’s, Applicants from underrepresented geographic areas

They buy lists of high-scoring SAT and ACT takers above a certain threshold AND with certain demographics that they want to target.

I’ve gotten tons of free applications, although not from top schools. My scores aren’t great, so being low-income does play a factor.