Twitter: a beguiling if paradoxical exercise in concise, social interaction. Paradoxical, in that a rhetorical nature renders it antisocial.

Fittingly, those opening sentences themselves could comprise a tweet, a short written expression made up of no more than 140 characters, the limit permitted by this chirpy social networking phenomenon.

Actually, they could be a "twoosh" - a tweet that uses its entire 140-character allowance. I wasn't just being a smarty-pants, I was being an annoying smarty-pants.

Tweets have become a sort of contemporary haiku, sometimes artfully worded moments of linguistic economy and inventive abbreviation. Whether these compressed sound-bytes are fascinating info-flashes cleverly shaped by the narrow funnel from which they emerge - or just so much twaddle - Twitter has emerged as the most talked-about cyber-nexus out there.

Great pander

There's plenty to wax philosophical about when it comes to Twitter, which is ironic considering the connotations of the word. For the purpose of this column, though, I think I'll keep it crass and pander to that morbid obsession which has of late become even more of an architectural carbuncle on our cultural landscape (cue showbiz fanfare): "celebrity". It's fair to say that Twitter favours the famous. It is, after all, a microcosm of the celebrity system, a community of people operating in various states of neediness, in search of an audience, working under the assumption that people will actually give a shit what they say.

It purports to be a libertarian information free-for-all, but functions as a meritocracy in the way celebrity culture does. Tweeters accumulate their audience (followers) at first through acquaintance and thereafter by recommendation based on how informative and entertaining their tweets turn out to be.

There are genuine Twitter celebrities, such as @shitmydadsays or @drunkhulk - individuals who have a following simply by being entertaining. The real leg-up the tweet ladder, however, can be provided by existing celebrity status. If you enter the Tweetosphere (or Twitterverse) with a preloaded public awareness, you are guaranteed a large chunk of followers. And yet "followership" must be earned and even if you are a known quantity, not bringing your A-game to the t(w)able can retroactively damage your credibility in the real world. The offender is demythologised, revealing the mundanity at his/her core and as such is unceremoniously "unfollowed". Of course there are some celebrities who don't even have to be witty or engaging - some are just followed, sheeplike, because they have nice hair or suffer from mental-health issues, both of which have their merits.

Group therapy

I resisted Twitter for a long time, initially because I didn't understand it. The IT whizz at Big Talk Productions, where I work, materialised in my office one day and suggested I secure my Twitter name in case somebody made off with it. I agreed this would be a good idea, desperate not to lose something I didn't know I had.

Thus my Twitter account was born and sat amid the melee like a dormant volcanic mouth. I didn't think about it again for a year and a half, until I discovered that my friend Nick Frost had started tweeting. Nick is equally, if not more, private than me and I was surprised that he had waded into the murky waters of this social quagmire.

Twitter is basically a way of making yourself available to a lot of people all the time, or at least giving them a conduit through which to reach you. At first, this exposure was the very thing that gave me pause. The internet has become a sort of group therapy for grumblers to validate their personal frustrations by publication. I did not want to go online and come face to face with someone from the Guardian film talkback, for instance, heaven forbid.

However, I noticed Nick was hand­ling the interplay without chagrin. The vast majority of his blossoming followership were funny and sweet, and rude people were simply "blocked", shut out of his tweet feed for ever, like rowdy drunks barred from a pub. If Nick enjoyed it, chances are I would. I started skulking, reading his tweets and enjoying the responses from his followers. I stood at the edge of participation like a kid on a diving board for several months before I finally took the plunge.

Lost in a good tweet

I can't even remember my first tweet, but it marked the beginning of a distraction that has lasted almost two years. Initially I saw it as a means to an end. I realised I had just over a year until Paul's theatrical release and it might be a good idea to gather followers with a view to using the site's marketing potential. Indeed, that's something I have done with enthusiasm. By the time Paul was released in February, I'd gathered close to a million followers and fully exploited their potential as an audience for the film.

Along the way, though, earning those followers was a lot of fun. I was given a helping hand by @stephenfry, who recommended me to his legion of friends, gaining me 20,000 new souls in just 24 hours. I took to tweeting with great enthusiasm, finding it a creative challenge to fashion mini-missives.

I created an elaborately fanciful personal life, featuring my dog Minnie as the central character. Last summer, my sister, @katypegg, @nickjfrost and I (@simonpegg) created a real-time Twitter event that involved us being abducted by an attic-dwelling demon, disappearing for a full three days, during which I released one sinister tweet in ancient Greek. We all then resumed normal tweeting three days later, to some disappointment among diehard followers who felt let down by the ending. (What was it, Lost?)

The point is, by the time I did have to start using Twitter for its marketing potential, I had grown fond of it. The haters never really materialised, with a few amusing exceptions, and I developed a fascination with this strange accessory brain at my fingertips.

Of course, I've somewhat cheated my way to the bizarre luxury of having the equivalent of a small city's population in my pocket, but I'd like to think I've at least partly earned it. Yes, I lose followers as well as gain them, but one of the positives about having a job which puts me in the public eye is that I get to exploit this modern oddity to the full. With all the corresponding negatives celebrity entails, that's surely something to crow about, let alone tweet.

“Paul" (certificate 15) is on general release