[ci5er]

First you have to separate out network effects (recently called "the platform stack") from virality. The former (not the one you asked for) is this stuff:

  - https://medium.com/@smitty/what-i-learned-from-100-s-of-hours-studying-platform-businesses-platform-building-basics-part-1-1ae6e75c6cf0

  - https://medium.com/art-marketing/the-platform-stack-c83f9c96e6

Slide #68 here talks about the difference (the whole deck is worth a look-see):

  - http://www.slideshare.net/a16z/network-effects-59206938/68-Whats_the_differenceD_E_F

Some of my clients have found spreadsheet/tutorial/example useful to help them "bring it home":

  - https://www.linkedin.com/pulse/20121002124206-18876785-how-to-model-viral-growth-the-hybrid-model

There's a slew of charlatans that will want to help you use FB to make things "go viral" (you'll find some of those pitches on SlideShare), but first, once you know what it is, you can begin to sort the wheat from the chaff for yourself...