The volume of Arabic messages has multiplied by 22 (+2 146%) in the last 12 months. Arabic is now the 8th most used language on Twitter, and Arabic messages represent 1.2% of all public tweets (2.2M per day). With recent events, Twitter has grown exceptionally fast in the Middle East. Although they are not part of the top 10 most used languages, Farsi (+350% in one year, but only 50K messages per day) and Turkish (+290%, 0.8% of all tweets) have also grown fast over the period.
For those wondering, English now makes up about 39 percent of tweets, showing the truly global nature of Twitter as a platform.