What $150 million buys you...
In building a community of passionate evangelists/advocates, one of the best (if not the best) place to start is with your existing employees.
And become a Fan.
And now, whoever is in charge of this effort (big kudos to you, btw), has a group of 672 people (some are employees, other potential employees) who WANT to have a tighter relationship
This is also a great example of the power of advertising within a social network. Since I've previously identified myself as a Microsoft employee and become part of the MS network, it is ridiculously easy to target an ad to me.
Comes back to the idea of the megaphone. Empower those already interested with more info so they can go out and "spread the gospel."