One of the things that I've traditionally found difficult to explain is the business case for the "branding features" in the onTap framework. So when this analogy hit me the other day I was pretty excited to have a simple explanation. Using the onTap framework, a branded application is a lot like a Virtual Private Server (VPS) for hosting. A VPS is a stable, scalable, low-cost alternative to dedicated hosting. A VPA is a stable, scalable, low-cost alternative to unique custom applications.
So I've created a page in the wiki that describes the forces involved in the problem and how a Virtual Private Application (VPA) resolves many of those problems. I even added a couple comic strips. :)
P.S. Editing help is much appreciated. :)