There are a lots of articles that explain the concept of lean startup but not as many that talk about how to apply it. Thanks for sharing. This should be helpful for anyone thinking about testing a two-sided network problem.
Changing behavior is difficult. That's the reason services like mint rely on bank/credit card transactions to get the data. You may want to quickly start testing with a few university students before investing more development time.
It is good that you have a narrow focus. What specific problem do university students have that is solved by your product? Also, have you thought about how you want to iterate with a small group of users?