At exactly 12:01 a.m. ET Saturday, on a first-come, first-served basis, the vast social networking site gave users the green light to claim variations of their names or other nicknames of their choosing.
Within three minutes, 200,000 usernames were registered, according to the social media blog Mashable, which covered the registration process live from Facebook's headquarters Friday night.
About 1 million personalized Web addresses had been claimed after an hour. And, through Sunday, Facebook said it had assigned about 5.75 million user names.
Late into the night, Twitter pages, Facebook walls and personal blogs broadcasted messages of celebration and disappointment, as Facebook users either locked-in their names of choice or lost out to others with the same names.
Stuart Miles, 33, editor of the gadget blog Pocket-Lint.com, who lives in Hoboken, N.J., was one of the unlikely ones.
Miles said he hopped on to his computer at midnight but failed to snag his name in time. "I wasn't successful," he said. "I just couldn't get on to the site and someone else got it."
That someone else appears to be another Stuart Miles in Australia. "He was just quicker off the mark than I was," Miles said. "It would have been nice to have but it's not the end of the world."
As he is originally from the U.K., he ended up claiming "StuartMilesUK" instead.
"We're planning to offer Facebook usernames to make it easier for people to find and connect with you," Facebook designer Blaise DiPersia wrote on the company's blog. "When your friends, family members or co-workers visit your profile or Pages on Facebook, they will be able to enter your username as part of the URL in their browser. This way people will have an easy-to-remember way to find you."
Although it didn't know what the participation level would be, the company said it had prepared for a spike in activity and had done quite a bit of testing. It said the registration process over the weekend went smoothly.
"It's rewarding to see the level of excitement about getting a Facebook username," said Larry Yu, a spokesman for Facebook. "It goes to show just how connected Facebook has become to people's sense of identity."
Some personalities and businesses, such as President Barack Obama and General Electric, have had personalized Facebook URLs for a while. But this change makes everyone with a personalized Web address more searchable on Google and Facebook.
Although an impressive number of Facebook users rushed to claim their URLs during the weekend, given that active Facebook users total about 200 million, the social networking site still has a ways to go.
Still, Adam Ostrow, an editor at the popular social media blog Mashable, thinks that in time more Facebook users will customize their pages.
"I think users of other sites are certainly used to having one and Facebook is promoting the fact that they're going to enable this," he said.