I think that varies a lot by discipline. Some schools target professional people who work full-time who are attending to get job promotions and have less time--MBA, criminal justice, education. The university I retired from in 2013 started a large online gradate program in education which attracted a large number of students and is a real money-maker.
Some small community colleges in rural areas are famous for offering easy online summer courses for college athletes to help their eligibility. Some of those schools have more summer students their fall/spring enrollment.
In "Cheated" about the University of North Carolina scandal for college athletes there were certain departments and courses athletes would be advised to take because they were "friendly" to the athletic department. It also provided a lot of funds to those departments and the professors got to travel to games with the team.