Here’s an idea from my NMS colleague Soren Dayton (R) — once you’ve built a core following for a Facebook Fan Page, try buying ads targeting the friends (and friends-of-friends) of your initial base. Since humans as a species tend to run with like-minded people, ads aimed at fans’ friends have a better chance of reaching someone interested in the same topics, plus limited targeting tends to drop the cost and increase the ROI for an ad buy. Overall, a clever way to leverage relationships, basically taking advantage of the same kind of network-based information-spread that lies behind viral marketing but with direct advertising. Plus, ads aimed at friends-of-fans can even mention that your mutual connection is already a Fan…peer pressure! You heard it here.