Track record goes a long way. You've proven to be effective in a very small 'niche'. You may want to consider taking seed (if needed) from F&Fs and then prove it in another city. You may find that expansion step to be useful. It will also help answer the question of expansion for potential institutional investors.
This is not a new model. The issue is it's VERY hard to scale. Proving it as much as possible before walking into a pitch will change the dynamic drastically.
You may also find that it does not scale as well as you hopes... or that managing college kids and relying on them to grow your business is not always reliable (that's a tough one).
Edit: I would have killed to have this service when I was in college. Props for making it work.
It cost big dollars to grow.
And yeah, the 150-school roll-out is divided by region, they're all primarily west-coast schools, and we plan to launch at a large school and then follow with all the smaller schools in the surrounding areas, just because their markets will overlap and it'll make our work easier.