“Twitter is not a media company,” said CEO Dick Costolo at the beginning of this year. Yet a number of recent developments have been threatening to prove him wrong.

Last week Twitter announced the launch of a #NASCAR hashtag page, where users can “discover the best Tweets, photos and perspectives from NASCAR drivers and their families, crews, commentators, celebrities and fans – all in a single timeline.”

In some ways, the page acts like a normal #search, with Tweets featuring the same hashtag collected together. However, Twitter’s #NASCAR page is presented with more visual content and a branded top banner, which makes it look more like a web page in its own right than a search function.

What really sets this page apart, however, is the fact that the Tweets are gathered through “a combination of algorithms and curation”. In other words, although the page uses Twitter’s automated search function, there is an editorial hand at work which chooses which posts to highlight.

Mathew Ingram at GigaOm writes, “Twitter is doing is very similar to what a site like Huffington Post or even a newspaper or sports site might do with an event like NASCAR. A traditional media outlet might also have a columnist write some thoughts about the race as well or send a reporter down into the pits to interview drivers, but pulling together real-time reactions from those involved and from spectators has also become a big part of the media response to a major event.”

Ingram writes in a later article that it would be easy to imagine Twitter using a similar system not just for sponsored events, but for news stories too, for example the revolutions in the Middle East or the earthquake in Japan.

Reuters’ digital and social media strategist Ross Neumann imagines the same scenario in a Tumblr post, where he also writes, “with hashtag pages, Twitter is essentially cutting out the social media editor, the middle man in content discovery.” In other words, Twitter can be seen as taking over a job that used to belong to new organisations.

Twitter has perhaps taken another step towards becoming more like a media company by hiring the Washington Post’s social media editor Mark S Luckie to act “as a liaison between Twitter and the journalism community.” Luckie told Journalism.co.uk that his new role would involve "forging partnerships with media organisations" and "coming up with creative ways that they can use Twitter, moving beyond hashtags."

Some media organisations are already involved in content partnerships with Twitter. The company announced on its blog yesterday that it has teamed up with media outlets including The New York Times, The Wall Street Journal and Der Spiegel Online to offer new “expanded Tweets”. This will mean that when users expand a Tweet linking to a story from one of these sites, they will be shown a preview of the headline and introduction, and sometimes the Twitter accounts of the publisher and author as well.

You can already expand and view content from YouTube and Instagram within the walls of Twitter. However, this new step puts Twitter’s expanded Tweets more on a par with Facebook’s social reader apps, which allow users to read articles entirely within Facebook’s own site. Twitter may be moving on from the place where you find news, to become the place where you read it as well.

With more direct cooperation with news organisations, more news content on its own site, staff members in editorial positions and curated content pages, there’s no doubt that the lines between Twitter and media outlets are becoming blurred. Mathew Ingram goes one step further: “it is showing signs of becoming a full-fledged editorial operation,” he says.

Sources: Mashable, GigaOm (1) (2) (3), Twitter (1) (2) (3), Ross Neumann, Journalism.co.uk