I think the larger issue is about getting user adoption. It is actually great case to have a situation where users overwhelm your service in a way that it outgrows a system such as this. If he ever gets that large, obviously there will be plenty of people looking to help him figure out how to make the storage portion feasible.
More interesting is the user experience. Creating something users can enjoy, agree with, and possibly part money for is a much more difficult problem to solve than figuring out to make large scale storage cost effective.