I'm still clueless as to how anyone ever thought they'd be able to make any money writing annoying apps for a free platform targeted at kids and young adults with no money...

There was VC funding for Facebook apps?

In my mind, a facebook app would be part of a wider strategy, such as integrating your external service into facebook to drive additional use of the core service. It didn't seem like many facebook apps on their own made that much sense, especially for VCs. I mean, they basically allow you to spread your ads across a small portion of facebook's site. As a business model for a couple dudes, fine, but as a model to throw millions of bucks on, not so sure there. Unless VCs were hoping facebook would acquire them, which it doesn't need to to benefit from them, so why would it?

The deeper realization may be that simply plugging holes in Facebook's existing functionality is a short term place to be.

But I think that there's probably more sustainability in bringing things to Facebook that they won't themselves.