You have a service that allows me to send in pictures of a whiteboard to get clean PDFs.
OK, what's the benefit to me as a user? If you can't answer that question, you'll have some issues getting users to sign up. Does it save me time, make me more money, reduce my headaches?
Maybe professors / whoever writes on whiteboards aren't your customers. For instance, When I was in college, the staff would pay people to take notes for disabled students. What if you set up a service where colleges could just have those types of people take snapshots of the board at various intervals. Then disabled students wouldn't have to worry about taking notes. You might even be able to get some grants, free press from non-profits and federal agencies.
It also might be interesting to think about how SlideShare and Flickr and other "send us files with pictures in them" type companies sell their products to the masses.