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Those who can't do, teach. And those who teach, when it comes to Facebook, are charging handsomely for the privilege. RockYou, a maker of Web "widgets," those Web pages in miniature that clutter up blogs and MySpace pages, has not, apparently, figured out how to make money directly off of the Facebook apps they've created like Super Wall and Zombies. The Sequoia Capital-backed startup has, however, figured out how to make money from Facebook app developers. How? By charging them to sign up users by advertising their apps on RockYou's Facebook apps. The fee? Half a buck per user. It sounds like the perfect Ponzi scheme: As long as venture capitalists and clueless big companies are overpaying for startups based on the number of Facebook users they've signed up, it should work brilliantly. After the jump, slides from RockYou's pitch to fellow application creators.

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"It's all you!" RockYou proclaims. Unless, that is, you're a Facebook app developer too inept to figure out how to get your app embraced by Facebook users.

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Take, for example, Yahoo. Until RockYou came along, Yahoo's music-video app for Facebook faced resounding indifference.

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RockYou has provided such amazing Facebook apps as Horoscopes and Zombies. If you've been "bitten" by a Facebook friend who wants to turn you into a zombie, now you know whom to blame — RockYou.

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Want to sign up users? It will cost you. At the largest volume discount, RockYou charges $0.50 per user signed up. That's roughly comparable to cost-per-click advertising on Google, which would be reasonable if, say, you were actually selling something, as opposed to trying to get people to sign up for your free Facebook app. And how does RockYou expect you to make up the money you've just spent on that user? Why, that's your problem. Perhaps you can charge that much for explaining to another startup how to make money on Facebook.

Full deck here (PDF).