There's a scene set in the near future in Jennifer Egan's Pulitzer Prize-winning novel, A Visit From the Goon Squad, in which a conversation between two people in a café becomes so awkward they conclude it via an instant-messaging service called T'ing, in which language is reduced to its most basic: 'GrAt. Il gt 2 wrk.' As one character remarks after the exchange, T'ing is "pure -- no philosophy, no metaphors, no judgements."

Whilst Egan understands what her character doesn't -- that even the most reduced linguistic exchanges cannot be "pure" -- the idea of appreciating social medias because they restrict self-expression is an interesting one in the context of our current eagerness to give sites such as Twitter increasing cultural relevance.

Last April the US Library of Congress announced tweets would be part of its archive, the Harvard professor Marjorie Garber recently noted that Twitter's "artificial limits on form [are] very good practice for writing and for reading", and James Poniewozik in TIME contextualised Twitter within "the history of literature [that] is the story of writers shaping their work to exploit technology."

Meanwhile in PORT magazine's inaugural issue this March, the journalist Ekow Eshun argued that Twitter is about creative self-expression, a place where "we curate our lives". He goes on, "people wanted to tell me that a 140-character limit is the enemy of good writing -- as if Hemingway or Carver or centuries of haikus hadn't made the case for concision."

The form may be similarly restrictive, but don't the how and why also define content? And Twitter's how and why is essentially anti-literary, anti-creative; Twitter is all about fitting in.

In literary Twitter circles, for example, clusters of publishers, authors, editors, journalists and agents build wide networks whose strength lies in blurring the distinction between professional contact and personal friend -- a blurring that makes group consensus all the more persuasive.

As Twitter's influence grows, instead of blithely thinking of it as a place of free expression, it might be a good time to wonder if the commingling of public and private realms doesn't potentially make expressing opinions more difficult?

Considered in this light, Twitter functions as banally as a school hierarchy: who to like, who not to, who you're allowed to criticise, who you can't etc. Whilst Malcolm Gladwell's article in The New Yorker last year enraged many with his claims that social networking was not instrumental to social change, his most salient point was that social media is "not the natural enemy of the status quo." Twitter relies on people's desire to be the same.

Nor is it really challenging from a linguistic perspective. Poniewozik writes, "Twitter is pure voice, an exercise in implying character through detail and tone", but the most striking thing about it is its uniformity of tone, how difficult it is to create any distinctive voice in its tight-lipped text box. Tweets can cause misunderstandings aplenty, but there isn't much room for subtlety.

Unsurprisingly, Twitter itself seems comfortable with its functionality, its stated desire only to transmit information. On its homepage it says, with knowing simplicity: "Follow your interests". So should we be a little more aware of its limitations?

Eshun reflects that Twitter's "merging of public and private self [is] the defining condition of the hyper-mediated modern age." The key word in the sentence is "merging". Twitter splices together public and private spheres, and doesn't have time for doubt. This is its commercial strength, but its creative and cultural limitation.