It's mostly about timing. Apple is a story for the decades. Facebook is a story for this year.

Photo: Martin Schoeller for Time

In Time's online poll, Wikileaks' Julian Assange was the people's choice -- and would have been ours as well. Steve Jobs was No. 7. Mark Zuckerberg was No. 10.

But the editors chose Zuckerberg. Why? Here's managing editor Rick Stengel's explanation:

For connecting more than half a billion people and mapping the social relations among them (something that has never been done before); for creating a new system of exchanging information that has become both indispensable and sometimes a little scary; and finally, for changing how we all live our lives in ways that are innovative and even optimistic, Mark Elliot Zuckerberg is TIME's 2010 Person of the Year.

Anybody who follows Apple (AAPL) can imagine a similar paragraph being written about Steve Jobs, an individual who has shaped our world as much as -- if not more than -- Mark Zuckerberg, and who has a business model that actually works.

So what does Zuckerberg have that Jobs doesn't? Let us count the differences:

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