NFL>college is a common misconception, making it a popular interview question for sports marketing jobs.
I was in the sports business for 8 years. College football in total has a larger fanbase (177mm+), over double the total attendance (43mm vs. 17mm) and generates more total money than NFL. Licensing alone generates over $4B at retail, surpassed only by MLB (College sports license market tackled by recession | Reuters). This isn't speculation but fact, pick up the Sports Business Journal or talk to any experienced marketer, the data is out there. The reason it doesn't "feel" that way is that the college market is fragmented across conferences and 100's of teams, while the NFL receives focused promotion by the networks.
NFL playoffs get higher ratings than bowl broadcasts but that's a separate issue.
What would those college football numbers look like if there were only 32 Division one football teams?