LONDON: Ten years ago today (Monday), a 29-year-old entrepreneur named Jack Dorsey typed five words - "just setting up my twttr" - into a website and pressed Send. It was a fairly mundane debut for Twitter, which would go on to become one of the world's hottest internet companies.
But Dorsey was hardly to know that. His previous start-ups had included a service to dispatch taxis and ambulances over the internet and a way to connect medical devices. So Twitter (as it would be known until the company's founders shrugged off their disdain for vowels six months later) was by no means a guaranteed success.
In the intervening years, the microblogging service has become an integral, some might say unavoidable, feature of millions of lives. It is the broadcast medium of choice for celebrities; it has built (and ruined) careers; and it is where news breaks before anywhere else: a recent study suggests emergency services can track storms and earthquakes faster using Twitter than traditional monitoring tools.
For better or for worse, the service is closely associated with major events and cultural movements, including the 2011 London riots, the Arab Spring, the Black Lives Matter movement and Barack Obama's 2008 grassroots ascendance to the White House. And for nine of Twitter's 10 years, it was the darling of the technology world: everyone who mattered talked about it and used it.
But the past 12 months have not been kind to Twitter. At the time of its IPO on the New York Stock Exchange in 2013, analysts feverishly predicted that Twitter could ride the same trends that had made Facebook a $100bn internet powerhouse with a population larger than any country. But the reality has been starkly different. Two-and-a-half years later, Twitter's user base is a fifth the size of Facebook's and has essentially stopped growing.
Despite the service's apparent simplicity - write a message of up to 140 characters and publish it, and follow people to see their tweets - a hidden complexity means that new users often find Twitter baffling. The service's unwritten rules of engagement, the work that new users have to put into following the right people, and the frantic nature of Twitter's real-time feed of messages, can be confusing to the uninitiated.
In the past 12 months, Twitter's share price has crashed. Last summer, the company returned to the past by replacing its chief executive of five years, Dick Costolo, with Twitter's visionary founder, six years after Dorsey had himself been removed.
The new leader has cut jobs, presided over a management exodus and reconsidered the fundamental and much-loved features that have served Twitter for the past decade. Last month, the service began showing users tweets arranged by an algorithm, rather than the simple chronological feed of messages people are used to. Reports of a plan to extend the 140-character limit, meanwhile, were quashed last week. Dorsey has so far failed to bring about the Steve Jobs-esque revival in Twitter's fortunes that was hoped for, at least when it comes to the number of people using the service.
However, Dara Nasr, Twitter UK's managing director, says Dorsey has had a hugely positive effect on the company.
"I'm more excited about Twitter than I ever was before and a lot of that is due to Jack and his vision," Nasr says. "What he's done is recognised there need to be changes.
"Often when there are changes made, people might not like them or understand them. But what he's been superb at is telling us that things need to change and what he's doing about that.
"He's been very clear to investors that things need to change - they'll take time but there's a plan in place and that's resonated."
The UK represents one of Twitter's healthiest markets. Nasr declines to say how many British users there are but points to independent figures suggesting roughly 18m. Revenue - largely from advertising - more than doubled to $140m in 2015. When it comes to the company as a whole, however, growth has been flat for the past six months, standing at around 320m users.
For all the hand-wringing about growth, Nasr says Twitter still has a not-unimpressive reach, especially when you count the 800m people or so the company claims are "logged-out users" - those who do not have accounts but might use the service anyway, or see tweets elsewhere on the internet.
"It's not a small figure, it's very much a global product, but yes of course we'd like to grow.
"What we want to do is show the respect and love we have for our existing 320m users and also open the door for other users," says Nasr.
He points out that Twitter is busier than ever: when Leonardo DiCaprio finally won an Oscar in February, there were 440,000 tweets a minute, a record for the service. Twitter representatives point to its power as an incubator for campaigns that have incited change and fostered solidarity, such as #NoMorePage3, demanding the removal of topless models' pictures from tabloid newspapers, and #JeSuisCharlie, in response to the Charlie Hebdo attacks in Paris that occurred in January 2015.
Last week, Kim Kardashian, one of the world's biggest internet celebrities, said Twitter was the place "where I can freely talk and have conversations with anyone and everyone".
But many users, those more partial to privacy, are less enamoured. Some feel that Twitter has become a hotbed for online abuse, with persistent harassment and bullying affecting their enjoyment of the platform. Twitter's public nature, the ability to hide behind a pseudonym and its free speech ethos have made trolling an immense problem.
Nasr says that the vast majority of tweets are not problematic, but that "if you were to hold a mirror up to society, society's not necessarily lovely".
"We're a platform for free speech, so it might seem more magnified on there," he says, but adds that "we couldn't take it more seriously than we do" and promises that Twitter will be doing more to combat trolling
Dorsey has outlined several other major priorities for Twitter, including the growth of Periscope, an app that allows smartphone owners to broadcast live video (one of Periscope's more unlikely successes occurred in January, when 20,000 people tuned in to watch a live video of pedestrians attempting to jump over a puddle in Newcastle).
Although the decline in Twitter's share price has levelled off in recent weeks, bringing a semblance of stability to the company, the man whose five-letter message began a huge social phenomenon has made it clear that massive changes are in the offing.
When most companies enter their second decade, their most volatile days tend to be behind them. But for Twitter, the biggest tests could still lie ahead.