1) Identify schools that have admission rates as close to 100% as possible (most schools are over 100%, not sure if ANY are below 100%, so like below 110% admission is very low).
2) Identify schools that have low student retention rates.
3) Look for folks in the Admissions department.
The selling process is like any other. Identify compelling cases for why they'd want/need your list. "Having trouble finding students? We can help"
Create your own funnel/campaign.
Document the process and verify their quality.
Cost per lead varies by quality.
There are multiple factors that vary here as well.
I'm not sure if you are asking about how to actually sell the online universities on the idea OR How to get the leads to then sell them.