According to this article, At Last — The Full Story Of How Facebook Was Founded, Mark Zuckerberg’s founding of Facebook was slightly devious, but no doubt, that little bit of ruthlessness and his generally risk-taking behavior at Harvard made his business succeed.

The story goes that on November 30, 2003, he was asked to write some code for an on-campus dating site called the Harvard Connection. Then on December 7, 2003, Zuckerberg wrote in private communication:

Check this site out: www.harvardconnection.com and then go to harvardconnection.com/datehome.php. Someone is already trying to make a dating site. But they made a mistake haha. They asked me to make it for them. So I’m like delaying it so it won’t be ready until after the facebook thing comes out.

Although it isn’t clear to me that Zuckerberg did not conceive of the “facebook thing” long before his meeting, for somebody who claimed he did not want to work under anybody else, it seems at least curious why he would accept spending time to write code for a similar site. On the other hand, he was skeptical about a straight dating site, designed facebook to be not primarily for dating but something more stealthily innocent (the right call). So it is possible that he was mostly concerned with the timing of the launches of two different sites, rather than their content.

In any case, the real shock is that the whole thing took only two months. The facebook domain was registered on January 11, 2004, and the site launched on February 4, 2004.