Earn money by Selling your notes Online

Sell your notes If you don’t mind sharing your notes with other students it’s a great way to generate a little extra cash. There are sites out there that you can upload your notes to, along with your price, and then when another student downloads them you get paid.
See five Crazy way to make money on Facebook

Most of these sites like Nexus Notes and Stuvia are free for you to list your notes but tend to take a cut of your profit in order