There is broad consensus that the social network needs to change, but no one knows quite how It's been nine years since Jack Dorsey sketched out with pen and paper the idea for a group SMS service, an idea that would go on to become Twitter.It's no exaggeration to say the social network has changed the way people around the world - including millions of South Africans - consume and share news and other information.More than anything else, Twitter has become a global platform for sharing ideas, be it breaking news or gossip.Journalists use it to report the news in real time, before it even goes into their publications. Celebrities and politicians, even presidents, use it to share their views - sometimes to their detriment.And many consumer-facing brands employ it to great effect as a customer service and marketing tool.mini_story_image_vleft1Most importantly, it has become a platform for free speech around the world.Yet, despite its apparent success - by May this year it had more than 300million active users - Twitter's future is far from secure. The company, which was listed on the Nasdaq stock exchange in November 2013, has seen its share price drift while rival Facebook's has shot higher on investor optimism.On its first day of trading, Twitter's stock closed at $44.90 per share, giving it a market value of $31-billion (about R380-billion). This week, Twitter's market capitalisation was more than 25% below that, at $23-billion.Facebook, which has 1.5billion monthly active users, is worth 10 times as much.Ironically, some critics say that Twitter's biggest selling point - its brief messages, limited to 140 characters - could also be its biggest fault.While Facebook and other social networks allow their users to share their thoughts in great (often excruciating) detail, Twitter encourages brevity. It forces people to craft their messages carefully. But this also limits expression and creativity.Some analysts believe this constraint could be turning users away.Indeed, a billion users who have tried Twitter have never returned.The University of Western Australia's David Glance, a columnist on The Conversation, pointed out this week that although Twitter's community of 300million active users might sound impressive, it is actually behind LinkedIn, Instagram (owned by Facebook) and even Google+.Twitter makes its money mainly from advertising, and the way in which it allows advertisers onto its platform seems more intrusive than on other social networks. Without this source of revenue, Twitter is dead in the water - but many users are turned off when they see distracting sponsored tweets in their timelines.story_article_right1Nor is there any obvious solution to Twitter's woes. Glance's view is that Twitter has no choice but to cut down dramatically on its expenses, which are running ahead of revenue growth."Doing that, while implementing transformational change, is going to be extraordinarily hard, if not impossible," he said.Perhaps it was performing this balancing act that proved too much for Dick Costolo, Twitter's CEO of the past five years, who announced this week that he would step down at the end of the month. Co-founder Dorsey - who also heads smartphone payments start-up Square - will take the reins until a replacement is found.Dorsey is an interesting choice, given that he was previously ousted from the company by fellow co-founder Ev Williams (who is still on Twitter's board).Dorsey will continue to run Square, splitting his duties between the two companies. There are worries he is spreading himself too thin. It's not clear if he fancies the idea of returning as permanent CEO, but the talk in Silicon Valley is that he wants the job full time.That would not be an easy ride for Dorsey. Figuring out how Twitter makes money will require a fundamental rethink of how the social network functions and what its business model should be. But, even if there is consensus that things need to change, few analysts agree on what it needs to do . Would it , for example, mean abandoning the 140-character limit and becoming more like Facebook? Or would it mean Twitter exploring opportunities to become more of a media company?No one knows. But what is clear is that the Twitter of a few years from now will look radically different from the Twitter that users know today...