Somebody asked 37signals why they don’t sell installable versions of their web apps for companies to host themselves. A wonderful response:
Here’s why: We would have to be a fundamentally different company to develop, sell, and distribute installable software. We probably couldn’t be as small, we certainly wouldn’t be as agile, and we definitely wouldn’t be as happy.
They realize there’s a bunch of money to be made there, but they don’t want it. To an MBA or an economist this might sound idiotic, but to me it sounds brilliant.