Seth Godin had a lovely little post the other day that I have been chewing on.  In More Perfect, he frames in a new way of thinking about something I think we all know, but never really accept:

You can lead a horse to water, but you can't make him drink.  - OR - Concentrate on the thirsty horses.

We all want to grow our networks of donors and activists.  More is better.  But where do you find that more?  I think a lot of our strategies have been focused on finding horses, and convincing them they are thirsty.  All those compelling action alerts we write.  The lists we rent and mail to.  We know that these strategies aren't super likely to find thirsty horses.  But we do them anyway, hoping that we'll convince a few they need a drink.

So here's another argument for the power of social networks.  

Your existing thirsty horses hang out at watering holes, where there are other thirsty horses.  If you can let go of your message, and let your stakeholders do the talking for you - your chances of success go way up.

This, of course, is not to say that your stakeholders in any way resemble horses.  They are all lovely people.