Twitter released its S-1 document on Thursday, giving potential investors and members of the media their first look at the numbers behind the popular micro-blogging site.
As journalists and potential investors flock toward the company's user figures and reported revenues, it's easy to overlook another aspect of the S-1 which may pose some food for thought: Twitter's self-identified risk factors.
See also: Twitter IPO: Who Gets Rich?
For Twitter, the biggest risk to the company's longterm viability seems to be the potential loss of user retention. Twitter has seen substantial user growth over the past few years, going from 167 million monthly actives last September to 218 million at the time of the filing, a growth of more than 30% in the past year. But the fear is that this growth will start to slow, ultimately leading to a plateau.
"We anticipate that our user growth rate will slow over time as the size of our user base increases," Twitter stated in the S-1. The company will need to rely on growth in foreign markets to make up for slowed growth here in the United States, the document continues.
It's only natural that user growth will slow, especially in the United States where adoption is already high. The key for Twitter will be increasing engagement with the users it already has, a task much easier said than done.
Twitter has spent the last several months working to build up that engagement, particularly around the area known as second-screen viewing. When television viewers aren't watching the game or their favorite TV show, Twitter wants to be their second screen, prompting conversation and discussion about those shows on the platform.
To ensure that this happens, Twitter has brought on a number of advertising partners in the last few months, including major partnerships with CBS and the NFL last week that will keep nearly-live television content on users' Twitter streams.
Another potential risk to the company: driving users away with an influx of ads and spam. Twitter will need to bring in revenue from somewhere, and ads already accounted for 87% of the company's revenues for the first six months of 2013.
"Twitter will be most successful if nothing changes from its user experience," Nate Elliott, VP and principal analyst at Forrester Research told Mashable last month. It'll be interesting to see whether or not the company is able to meet Wall Street expectations without negatively altering the user experience.
Twitter also mentioned that continued consolidation by competitors like Facebook, Google, LinkedIn and Yahoo could reduce Twitter's functionality with other apps, citing Instagram as a primary example. When Facebook bought Instagram last year, Twitter users were no longer able to embed photos within tweets. Instagram photos now shared on Twitter contain a link that send users back to Instagram.
"Any similar elimination of integration with Twitter in the future, whether by Facebook or others, may adversely impact our business and operating results," according to the S-1.

Twitter's IPO Filing from Mashable
Arrested
One of the earliest examples of Twitter's ability to make change came when one young U.S. student secured his release after a wrongful arrest.
On April 10, 2008, James Buck, a University of California, Berkeley grad student was photographing an anti-government protest in Mahalla, Egypt, when he was seized by the authorities.
He managed to send a quick tweet -- "Arrested" -- which prompted his followers back home in the U.S. to contact not just the University and the American Embassy, but also media organizations, that were able to put pressure on the Egyptian authorities.
The digital communique worked. On April 11, Buck sent another one-word tweet. It simply read: "Free."
Are you ready to celebrate? Well, get ready: We have ICE!!!!! Yes, ICE, *WATER ICE* on Mars! w00t!!! Best day ever!!
When the Mars Phoenix found evidence of H2O on on the Red Planet in June 2008, it wasn't just the discovery that made headlines, it was also the way the organization choose to break the news.
Rather than via an official statement or formal press conference, the news broke through the Mars Phoenix Twitter account. NASA issued a tweet that read "Are you ready to celebrate? Well, get ready: We have ICE!!!!! Yes, ICE, *WATER ICE* on Mars! w00t!!! Best day ever!!"
The fact that an informal tweet could be used to share such an important discovery caught many major news outlets off guard, with many not picking up on the story until hours after.
As far back as 2008, this tweet demonstrates that Twitter was becoming a platform where not just citizen journalism reports might emerge, but where major organizations might choose to share important news.
The average citizen could hear breaking news at the same time as media outlets helped establish Twitter as a must-watch service to monitor.
http://twitpic.com/135xa - There's a plane in the Hudson. I'm on the ferry going to pick up the people. Crazy.
One tweet from early 2009 has been used time and time again to illustrate not just the power of Twitter's potential for "citizen journalism," but the "old media versus new media" battle.
When a U.S. Airways plane crashed into the Hudson River in New York, Twitter-using witnesses immediately tweeted about the incident. The crash news hit Twitter a full 15 minutes before the mainstream media got hold of the story, a time period that's arguably an age as far as breaking news goes.
One of the first, if not the first to tweet, was Brooklyn-based Jim Hanrahan who wrote: "I just watched a plane crash into the hudson rive[r] in manhattan."
But it wasn't Hanrahan's tweet that went viral. It was a tweet from Janis Krums, a passenger on a nearby ferry, that was accompanied by a Twitpic image of people being rescued from the downed plane.
The news spread fast, and along with it, Krums' photo. TwitPic crashed from sheer volume of traffic, by which time Krum's iPhone snapshot had been established as the lasting visual memory of the incident.
HI TWITTERS . THANK YOU FOR A WARM WELCOME. FEELING REALLY 21st CENTURY .
Just when did Twitter go mainstream? It's hard to pin down the exact moment when the service went from Silicon Valley's favorite short-form social platform to micro-blogging for the masses, but there are some milestones worthy of mention.
One such event took place in 2009, when the first lady of American television Oprah Winfrey broadcast a Twitter-themed version of her popular talk show.
During the taping of the show, Oprah Skype called Ashton Kutcher, helping him win his much-publicized battle with CNN to become the first Twitter account with more than a million followers, and Twitter CEO Evan Williams appeared as a guest.
Oprah had announced before the broadcast that she was to send her very first tweet, and as her newly-set up "Oprah" account racked up more than 100,000 followers before she had typed a single word. Horrified early adopters made snarky comments about "soccer moms" ruining the site and predicted an unwanted appearance by the fail whale.
Oprah Twittered like your mom would. With dubious punctuation and shouting in all caps. Her first tweet read: "HI TWITTERS . THANK YOU FOR A WARM WELCOME. FEELING REALLY 21st CENTURY ."
While the long-term impact of Oprah's on-air Twitter exploits can't be measured, Hitwise did offer immediate insight into the "Oprah Effect" on Twitter.
Twitter's U.S. Internet visits increased 24% on the Friday of Oprah's first televised tweet with 37% of traffic from new visitors.
@Oprah now has over 21 million followers.
We regretfully admit that something has happened off of the Gulf Coast. More to come.
In late April 2010, an explosion at the Deepwater Horizon oil platform in the Gulf of Mexico resulted in a massive oil spill.
A few days later a Twitter account was created with the handle @BPGlobalPR. The account's first tweet read "We regretfully admit that something has happened off of the Gulf Coast. More to come."
A second tweet soon followed. "Adorable! Naughty Kitty Makes a Mess! http://www.youtube.com/watch?v=greOQOD6GDA."
While parody accounts were nothing new, the sheer audacity of the BP Global PR spoof account was notable. As further details emerged about the extent of damage the catastrophic spill would cause, BP Global PR tried to flog t-shirts.
During the year when "Gulf Oil Spill" was the top trending topic, a parody PR team arguably held more Twitter clout than BP's official account.
In May 2010, a week after launch, @BPGlobalPR boasted more than 55,000 followers. @BP_America had just under 7,000.
Crap! Robin Hood airport is closed. You've got a week to get your shit together, otherwise I'm blowing the airport sky high! #IAmSpartacus
In 2010, we learned about the power of Twitter to protest perceived injustice.
In January of that year, UK accountant Paul Chambers had tweeted a joke about Sheffield airport being closed by snow. The tweet read: "Crap! Robin Hood airport is closed. You've got a week and a bit to get your shit together otherwise I'm blowing the airport sky high!!"
Chambers' punishment for writing a poor-taste tweet was criminal prosecution for sending a "menacing" message via a "public electronic communications network."
In May 2010, Chambers was convicted and fined for the offense. Understandably, the trial was big news on Twitter with people following and commenting on the proceedings using the hashtag #TwitterJokeTrial.
In November, when Chambers lost his appeal against the conviction, and was ordered to pay thousands more in costs, the Twitter community stepped up to protest the decision. UK singer-songwriter Chris T-T suggested people should tweet Chambers' original joke, "Spartacus style."
The suggestion caught on and thousands flooded Twitter with the original "menacing" words along with the hashtag "#IAmSpartacus." As UK celebrities and media figures joined in, the hashtag quickly became the leading worldwide trending topic.
Chambers won his high court appeal against conviction in 2012, with the final ruling hailed as not just a victory for freedom of speech, but common sense.
Re Egypt tweet: we weren't intending to make light of a serious situation. We understand the sensitivity of this historic moment -KC
Big brands have made some big mistakes on Twitter. Over the years we've seen some of the most vocal outrage aimed at companies that have tried to take advantage of trending topics to highlight their products and services.
Hurricane Sandy, the Japanese earthquake and the revolution in Egypt are all world events that ill-advised corporate Twitter accounts have tried to link to their marketing activity, with disastrous PR fails as a result.
One particularly notable example of this kind of activity is from fashion brand Kenneth Cole. In February 2011, during mass political protest in Egypt, the @KennethCole account tweeted: "Millions are in uproar in #Cairo. Rumor is they heard our new spring collection is now available online."
Twitter's reaction was instant and very negative, showing that brands shouldn't mix current events and marketing, even if they're just trying to make a joke.
Gap, American Apparel, Habitat, Urban Outfitters and Bing have all committed similar offenses. We're highlighting Kenneth Cole, because despite an apology at the time of the #Cairo tweet, the brand seems pretty unrepentant about using current affairs to promote its goods.
In early 2012, McDonalds helped teach Twitter-using brands a valuable lesson. McDonalds' major marketing mistake was assuming that it could create and promote a hashtag, sit back and reap the positive benefits.
A two-pronged approach, McDonalds penned several tweets encouraging its followers to get involved and share stories. One prong looked at McDonalds' suppliers, with the hashtag #MeetTheFarmers, the other shared a link and read: "Meet some of the hard-working people dedicated to providing McDs with quality food every day #McDStories."
The #McDStories hashtag did gain traction, but unfortunately for the fast food chain, it mutated into a full-on consumer backlash against the brand with people using the opportunity to vent their dislike of McDonalds, its business practices, and its food.
With #McDStories tweets containing tales of fingernails in burgers, food poisoning and more, McDonalds quickly pulled the plug on the Twitter campaign.
A McDonalds marketing exec later admitted it didn't go "as planned."
Power out? No problem. pic.twitter.com/dnQ7pOgC
When the lights went out and the action stopped during the third quarter of Super Bowl XLVII in February, the U.S. public provided a fascinating real world example of "second screen" viewing as people's attention turned from the television to social media.
Oreo made the most of this unexpectedly engaged audience with a clever tweet that read "Power Out? No problem" along with an image of an Oreo cookie with the caption, "You can still dunk in the dark."
The tweet's timing -- it went out within minutes of the power outage -- and its light-hearted, shareable message presented in an eye-catching way -- went viral. With 15,000 retweets, Oreo's message quickly became a trending topic.
Oreo wasn't the only brand that thought on its feet that night, but with an entire social media team poised to react to anything that might happen during the game, including copywriters and artists, the cookie's team showed both the benefit of being prepared, and the power of real-time marketing on Twitter.
All: The main @AP Twitter account has been hacked, The tweets coming out of there are false. We are working to correct the problem.
In April 2013, a Twitter account hack starkly demonstrated just how far Twitter has come, and how seriously the social network is now taken.
The Associated Press' main Twitter account was hacked and issued the following tweet: "Breaking: Two Explosions in the White House and Barack Obama is injured."
While it's understandable that Twitter users that saw the tweet were temporarily taken in by the "breaking news," what's staggering in this instance is that the U.S. stock market was affected.
The Dow Jones dropped over 140 points, and although the AP was quick to suspend the hacked account and the market recovered in minutes, the hack proved Twitter's impact across sectors of the U.S. economy.
Image: Kurt Wagner/Mashable