"I've been digging through all my drawings, emails, & notes from around that time. I'll share them over the next 2 weeks right here on #twttr," Dorsey tweeted.
By comparison, it took three years, two months, and one day for Twitter to grow from its first to its 1 billionth tweet, according to the company.
On March 21, 2006, Dorsey -- @jack -- sent the first tweet: "inviting coworkers."
As the world now knows, more than Twitter employees responded. On March 12, 2011, alone, 572,000 new Twitter accounts were created, wrote Carolyn Penner of Twitter's communications department, in a company blog. On average, there are an average of 460,000 new accounts created each day, she wrote. In addition, there was a 182% increase in mobile users over the past year, Penner said.
In the last month, all the company's users sent an average of 140 million tweets per day, according to Twitter. By comparison, last year, they sent an average of 50 million tweets per day, Penner said.
Events such as the tragic earthquakes and tsunami in Japan, the deaths of famous figures, and holidays spark surges in Twitter usage. For example, the death of Michael Jackson generated 456 tweets per second on June 25, 2009 -- a record at the time, said Penner. The current record of 6,939 tweets per second was set at four seconds after midnight in Japan on New Year's Day this year, she said. When Japan was hit by the earthquakes and tsunami, Twitter users sent 177 million tweets in one day.
"Today, on every measure of growth and engagement, Twitter is growing at a record pace," said Penner.
The name that has become synonymous with microblogging was the creation of Noah Glass, part of the small team behind Twitter, said Dorsey. Other original company members included Keith Florian, Biz Stone, and Evan Williams.
"The team was small: @Noah came up with the name & managed, @florian & I programmed, @Biz designed, all under the roof of Odeo & @Ev. #twttr," Dorsey tweeted.
Odeo, originally developed by Glass and Williams, was a directory and search destination Web site for RSS syndicated audio and video. In 2007, Sonic Mountain acquired Odeo; today, Odeo Enterprise Media Platform develops Web-based video architectures for businesses.
To keep up with this growth, Twitter's staff has expanded. In its early days, the company had an eight-member team. Today, it has 400 employees, the company said. In fact, Twitter is outgrowing its San Francisco headquarters, prompting city officials to lure the company with financial incentives, according to published reports. In January, Twitter reportedly reviewed a 200,000-square-foot complex vacated by Wal-Mart in nearby Brisbane, Calif. San Francisco officials want to hold onto a company they expect to grow to 3,000 employees over the next decade, the Bay Citizen said.