The timing of Twitter's IPO news came as a shock to many since it was widely speculated that the company would wait until 2014 to take the company public.
(Read more: Twitter files for long-awaited IPO)
After all, Twitter execs—including CEO Dick Costolo—have been adamant that the company is not in a rush to go public.
But there's a few reasons why Twitter's move to become a public company isn't so surprising.
First of all, the conditions for a social media IPO are just about as good as they could get.
"This is a really different market," Francis Gaskins, president and editor of IPODesktop.com, said Friday on CNBC. "The averages are up about 23 percent from where they were when Facebook went public, that's huge news. Facebook itself is up 150 percent, so the cards are well positioned for Twitter."
Facebook and other social media companies have seen their share prices take off recently. In fact, Facebook reached a new record high on Thursday of $45.62 and on Wednesday LinkedIn's share price hit a high of $257.56.
In addition, the number of IPO filings is going up overall. Filings through August of this year increased more than 40 percent compared with the same time period last year, according to Renaissance Capital IPO Research.
Another reason for a Twitter IPO now is so it can show investors accelerating growth in its business.
Unlike Facebook, whose growth appeared to be slowing during the run-up to its IPO, industry analysts estimate solid growth in Twitter's business over the next year.
The microblogging site, which has an estimated value of $10 billion, is estimated to have earned about $250 million in revenue last year and is predicted by many industry experts to be on track to earn $500 million in the 2013 calendar year and $1 billion in revenue in 2014.
"It has a very defensible position, there's no competition, it has a great reputation," Gaskins said. "It''s been groomed, it has great sales."
One of the key areas Twitter is growing in is mobile, which also gives it an edge in its IPO process.
"Twitter is in a different space, as when Facebook went public, they had no mobile revenue. Twitter, the estimations I've seen this year is $250 million in revenue last year, over $500 million this year, but more than half of it is going to be driven by smartphones and tablets," Dan Niles, CIO of Alpha One Capital Partners, said Thursday on CNBC. "So they are in a different spot going public than Facebook was."
(Read more: Twitter IPO interesting at right price)
Finally, because Twitter is taking an unusual path to going public, its actual IPO may not even occur until 2014, which is exactly when many were speculating that it would happen.
Instead of a public filing, Twitter submitted its documents to the SEC confidentially, which is a new provision provided under the JOBS Act to companies making less than $1 billion.
The confidential filing basically allows the company to work with regulators on its plans before actually making them public.
The process for filing a confidential registration statement to actually selling shares to the public is typically lengthy. On average, this process runs about 136 days, according to research by the Latham & Watkins law firm.
After the initial confidential submission to the SEC, the agency takes about 30 days to get back to the company with its comments. Then the documents need to be redrafted, resubmitted and there's potentially more comments or revisions to be made.
Typically the company will file at least two confidential submissions before the public ones are released, according to Latham's research. When the public S-1 is filed, it will include copies of the earlier confidential drafts.
The company filing—in this case, Twitter—has to make its S-1 public at least 21 days before it begins its roadshow to court investors. But the average company takes about 49 to launch a roadshow after its first public filing, according to Latham's research. And then the roadshow can last any number of days.
So if Twitter follows the same pattern as those who have already taken this course to going public, there's a chance it may not have its IPO until the first quarter of 2014.
—CNBC's John Carney contributed to this report.
—By CNBC's Cadie Thompson. Follow her on Twitter @CadieThompson.