There are some three types of ads you are likely to hear in college radio stations.
The first type of ads you are likely to hear in college radio stations is that of ads for recreational services, placed by recreational establishments located around the colleges. Students are known for their heavy partying lifestyles, and there are always businessmen keen on taking advantage of those.
The second type of ads you are likely to hear in college radio stations is that of ads for items on sale (mostly things like old books), placed by members of the student body. Alongside those, you are likely to hear ads for lost and found items as well ads placed by students who have lost items, pleading with those who may find them to return them.
The third type of ads you are likely to hear in college radio stations is that of ads for student loans. These are typically placed by loan sharks, targeting students who were unable to get enough funding after filling in the free application for federal student aid at www.fafsa.gov or the local college student finance office. The loan sharks in question, typically presenting themselves as fairly respectable financial institutions, are usually willing to lend such students who are in financial distress, but at astronomical interest rates, and typically with hard-to-bear repayment terms.