Ask HN: Revenue model ideas for a website?

Me and my two friends have started a website where we upload our college syllabus, practicals, previous years question papers, notes and also posting video lecs from youtube... We're getting good response from the students. Currently we're getting 100-150 page views per day and during exam time 300-400 pageviews. We've plan to extend our site to more colleges...

So I'm asking some ideas on how can we get revenue from this site? Recently we've added Adsense to our site... but not sure whether it will work or not..as we're new to adsense.

Here is our site - http://www.myclgnotes.com/

Thanks.