Many Americans would have been surprised that Jakarta was the largest contributor of tweets, a city. I was not. It is a large city (10 million), phones with QWERTY interfaces are all the rage, and Bahasa Indonesia uses the Roman characters.
What surprised me was Riyadh. It is not an extraordinarily large city (4.75 million). What is going on in Saudi Arabia? Expats frustrated by the traffic? Saudis frustrated by geriatric government?
Unsurprisingly, Tokyo ranks second. London ranks third, and the next city in the U.K. is Manchester and accounts for about 0.4% of all public tweets geo-localized at the city level. The first U.S. city is New York and only ranks 5th. As a sign that Twitter grew out of its homeland, San Francisco, where the company is headquartered, represent less than 0.2% of all tweets geo-localized at the city level.
Arabic usage continues to grow on Twitter: it is now the 6th language with 2.8% of all public tweets posted in June 2012. As another sign of this growth, Riyadh is now the 10th most active city, and the number of registered users in Saudi Arabia grew by +93% in six months, reaching 2.9M.