They're promoting and "investing" into Facebook apps because they're major investors in Facebook and will benefit from Facebook IPO. More apps, bigger the IPO!
In any case, it has nothing to do with them wanting YOU to succeed.
I'm also slightly amazed at the willingness of developers to create apps for the Facebook platform, since it's closed and controlled by a single corporate entity.
Have people forgotten (or are too young to remember) the days when MS completely dominated the development platform, and the economic consequences for 3rd party software companies?
The web app revolution is supposed to be all about breaking out of that pattern (which is why MS fought Netscape so hard).
In any case, it has nothing to do with them wanting YOU to succeed.