I am currently researching e-Learning, and I'm hoping to launch a service similar to Khan Academy in the next year. It would offer learning tools for students all over the world. How should such a service be monetised (i.e. start to make a profit) over time? How feasible is it?
There are 2 main ways to monetize an online product:
Pros: Easy to get started with products like AdSense (Google's platform). If/when your traffic gets a steady/high traffic (over a million impressions a month) you could try to sell ads at higher rate or get sponsorship deals.
Cons: It will probably not be enough to cover the cost of operations in the early years (sorry, yes it could take a few years to start making profit) unless traffic grows fast.