Facebook announced another milestone yesterday. The social-networking site now has 250 million registered users.

It seems like only yesterday when we were discussing the 200 million mile marker. OK, so technically, "yesterday" happened in early April. But you still have to be impressed. How often do you see a company this big grow its user base by 25% in a little more than three months?

Question time: What will be larger by year's end -- Facebook's user base or the U.S. population?

Bonus question time: Who do you think feels the most stupid at this point?

I'm leaving Microsoft (NASDAQ:MSFT) out of the walk of shame, because at least it was able to square away an online advertising deal with Facebook, in exchange for paying up for a minority stake in the rapidly growing site.

Since Facebook isn't yet a public company, we don't know how well it's monetizing its traffic. We do know that its throughput is massive. Nielsen data for June finds that Facebook attracted 87.3 million unique stateside visitors last month. Google, Microsoft, Yahoo!, AOL, and News Corp. drew larger crowds, but Facebook's average user spent nearly 4 hours and 40 minutes on the site. None of the other dot-com heavies came even close.

If you multiply the audience by the hours spent per person, only Yahoo! was more magnetic. Facebook is likely to overtake Yahoo! this month, and it's crazy if it doesn't take that crowning achievement as a sign to go public.

Isn't that the best way to make its flawed list of potential suitors eat bucketfuls of crow?

The market has been kind to the recent Web-based IPOs for OpenTable (NASDAQ:OPEN) and LogMeIn (NASDAQ:LOGM). It's time for Facebook's close-up now.

Some other Facebook status updates:

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Longtime Fool contributor Rick Munarriz remembers when social networks were an offline endeavor. He owns no shares in any of the companies in this story and is also a member of the Rule Breakers analytical team, seeking out the next great growth stock early in its defiance. The Fool has a disclosure policy.