The Gaping Hole in Facebook's Story: Mobile

NEW YORK (TheStreet) -- Facebook(FB) says it deserves to be worth more than $100 billion because it's a platform.

But that's true only on the Web.

Like CompuServe, AOL(AOL) and Yahoo!(YHOO) before it, Facebook is a destination. It bids to become the whole Web for its users, and for its most loyal users it is. It is, after all, where their friends are. When you're seated behind a screen, Facebook may be your primary platform for interacting with the world.

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But when these friends leave their PCs and take up their Apple(AAPL) iPhones, Facebook is, at best, an app. The phone itself is the platform. And Facebook has no control over the phone.

Apple controls the phone. Its policies and financial demands are behind any company's interaction with customers on the iPhone. Whatever they do, whatever they sell, Apple takes its cut.

That's why so many recent Facebook acquisitions are in the mobile space: Strobe; Tagtile; Instagram; and, most recently, Lightbox which makes a photo-sharing app for phones using Google's(GOOG) Android operating system.

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But no matter how many of these companies Facebook buys, and no matter the merits of each acquisition, what Facebook is still left with is a collection of apps. You don't go to Facebook and then use that platform to get Instagram for your mobile phone. You get Instagram for your mobile phone.

This is a big part of the problem with any destination business model. You may become the biggest destination on a platform, but when the platform changes, you have to start all over again.