Twitter is a pretty useful tool for city-dwellers. You can track transit hiccups. You can follow new bars that don’t even exist yet. You can exchange hilarious quips with friends, without actually venturing onto the busy streets to meet up with them.

In 2012, Semiocast, a market research company, decided to study over 1bn tweets sent in June that year, to find out which city tweets most and why. Many of its finding were pretty unsurprising: the US had the most Twitter accounts (over 140 million); English is the most widely-used language on Twitter.

When they looked at which cities tweet the most, however, things got more interesting. Second and third places went to Tokyo and London – but in the number one slot was Jakarta, Indonesia. Badung, another Indonesian city, was also in the top ten. Here’s a chart, showing their top 20:

Perhaps excited by this unexpected victory, Brand24, an Indonesian social marketing company, conducted another study in 2013, this time looking at 10.3 billion tweets from January to March of that year. Jakarta made the top spot again. In fact, tweets from Jakarta, which contains 0.28 per cent of the world’s population, made up for 2.4 per cent of the world’s tweets during that period.

This meteroric rise is perhaps surprising for a different reason, too: it’s a relatively recent development. GNIP, another social media analysis company – there are, it seems, loads – found that in 2008, tweets in Indonesian accounted for 0 per cent of the total (we assume they rounded down). By 2013, it was the fifth most commonly tweeted language, accounting for 3.25 per cent of the world’s tweets.

So why are Jakartans so tweet-happy all of a sudden? Here are a few possibilities:

It’s the second largest city in the world.

Neither study on tweet locations adjusted for city size: instead of tweets per resident, they compared raw numbers. Depending on how you define the city limits, Jakarta has a population of somewhere between 10m and 30m; it might be the second largest city in the world; it’s certainly in the top 20. What’s more, half of its residents are under 30. In 2013, 79 per cent of the world’s tweets came from people under the age of 30. Do the maths.

It’s also one of the most densely populated cities in the world.

This is important, but not for the reasons you might expect. When the news broke of Jakara’s Twitter eminence in 2012, an official commented that it was probably because they spend so much time stuck in traffic. In 2010, a city governor even called on residents to tweet traffic news on Twitter, in order to ease congestion in the city. Lots of people in a small area means lots of waiting around, and lots of idle time to spend on your smartphone.

Jakartans “love to chat”.

Budi Putra, ex-editor of Indonesian Yahoo!, says that Twitter is huge in Jakarta because Indonesians love chatting to one another.  He also says many Jakartans use Twitter as a form of messenger, rather than a microblogging platform. This makes it likely that users tweet more often than the average user, as they’re having conversations rather than just airing their thoughts.

Blackberry and Yahoo! messenger are also popular in the city, which seems to back up Putra’s “Jakartans love to chat” thesis.

Tweeting pays.

In 2013, it emerged that Jakartans with over 2,000 followers can be paid upwards of US$21 per tweet to advertise products or events. Confusingly, these sponsored tweeters are called “buzzers”.

The influence of Twitter in Jakarta, and Indonesia as a whole, isn’t lost on those looking for influence.  In the recent presidential elections, one of the two candidates, Prabowo Subianto, had 75 young people running his social media campaign. Turns out, even that wasn’t enough: as of June, he had Twitter 750,000 followers to his opponent Joko Widodo’s 1,600,000. Perhaps unsurprisingly, Widodo (governor of Jakarta and also, incidentally, known for his love of Metallica) took home 53 per cent of the vote.

Joko Widodo: governor; president-elect; king of Twitter. Image: Getty.

Celebrities are taking advantage of Jakartans’ Twitter dominance, too. Agnes Monica, or Agnez Mo, the Indonesian singer and actress, has almost 11 million followers. That’s only a quarter of Lady Gaga’s , but Google trends data shows that Lady Gaga is searched on Google more than than twenty times as often, so Monica is reeling in a bigger following than her popularity would suggest. We can only imagine she’s followed by millions of Jakartans, stuck in traffic and avidly reading her every tweet.