Does The Web Juice Non-Fiction?

Tyler Cowen's hunch:

I...see overwhelming evidence that the internet gets people to read and write more.  The latter is probably a good thing.  I also believe the internet leads to less interest in long novels and more interest in non-fiction.  I won't judge that one, but it's misleading to cite only the decline of interest in long novels and by the way don't forget Harry Potter, the form is hardly dead.