WHEN the news came, it was delivered appropriately in the form of a tweet. On September 12th Twitter revealed via its own micro-blogging service that it had begun a process with America’s Securities & Exchange Commission that should ultimately lead to an initial public offering (IPO) of shares in the company. Should the firm’s plans go through, the IPO is likely to take place in 2014. Twitter’s listing will be the most eagerly anticipated tech-company flotation since Facebook’s, early last year. Assuming that nothing derails it, Twitter’s IPO will be significant for several reasons. It will further underline the power of social media—in Twitter’s case, short text messages of no more than 140 characters—as a tool for mass communications. It will mean that the all of the biggest social-media behemoths, including Facebook and LinkedIn, will have left the shadows of private ownership for the spotlight of the public markets. And it will add another dimension to the growing rivalry between America’s leading tech firms, who are increasingly invading one another’s strongholds.

Quite how high a valuation Twitter will find is hard to say, though estimates range from $10 billion to $15 billion or more. The firm has taken advantage of a rule that lets companies with less than $1 billion in revenue file for an IPO confidentially (eMarketer, a research firm, reckons Twitter’s sales will be $583m this year). So details about the company’s performance and prospects, as well as the percentage of its equity on sale, will only become public shortly before an investor roadshow kicks off. Goldman Sachs will be the firm’s lead investment-banking adviser on the deal.

Twitter will be anxious not to ruffle investors’ feathers in the way that Facebook did. The bungled flotation of Mark Zuckerberg’s giant social network led to its share price trading well below the $38 offering price for many months. It recovered this year and, as it happens, hit a new high of over $45 during trading on September 11th.

The fact that memories of Facebook’s debacle have faded is no doubt one reason that Twitter has decided to file for its public offering now. A recovering IPO market in America, which is on course to have its busiest year since the financial crisis, is also likely to have encouraged Twitter’s executives to take the plunge. The firm, which has more than 200m monthly users, is still growing fast. And it can boast that the arrival of a number of seasoned executives this year has bolstered a management team led by Dick Costolo, its respected chief executive.

Twitter has another thing in its favour. The company has focused its service primarily on smartphones and other mobile devices, so it stands to benefit as more and more communication shifts to such platforms. Its popularity with political activists, pop-stars and politicians has also helped to make its brand a household name around the world.

Still, Twitter will have to overcome doubts about its business model. One of these is whether the company will be able to generate much bigger revenues without alienating customers who object to seeing ads sprinkled across their phone screens. Another is whether Twitter will be able to see off rivals such as Facebook, which has introduced features that allow its users to conduct real-time conversations like those on the micro-blogging service.

To help address these challenges, the company has been on an acquisition spree. Earlier this week it snapped up MoPub, a mobile-advertising company in San Francisco, for an estimated $350m. MoPub’s technology will be used for real-time bidding for ads that run on Twitter. This will enable the firm to target these ads better and charge more for them. MoPub will also help Twitter place the ads it sells on other mobile networks, taking a cut of the revenue generated. Both capabilities will make Twitter a more powerful competitor to the likes of Google and Facebook.

Other acquisitions Twitter has inked this year, including Trendrr, a social-media analytics company, and Bluefin Labs, will also strengthen its hand. Bluefin, for instance, makes software that allows marketers to identify users tweeting about particular TV programmes and lets them send messages to those viewers.

Knitting all of these businesses together will not be easy. Nevertheless the acquisitions are a sign of Twitter’s determination to grab a leading role in the fast-growing mobile-ad market. Twitter’s logo is a cute little bird. But to win in the brutal battle that lies ahead, it will need to show it has the killer instinct of a bird of prey.