Johannesburg is the top tweeting city in Africa, with two other South African cities among the continent's top five Twitter centres, according to the second How Africa Tweets study from communications company Portland.
The study, released by London-, New York- and Nairobi-based Portand on Tuesday, analysed geo-located tweets originating from Africa during the last three months of 2013.
Johannesburg takes the number one spot on Portland's list with 344 215 geo-located tweets during this period, followed by Ekurhuleni (the metro municipality east of Johannesburg) with 264 172 tweets, Cairo, Egypt with 227 509 tweets, Durban with 163 019 tweets, and Alexandria, Egypt with 159 534 tweets.
Kenya's capital Nairobi was the most active city in east Africa and the sixth most active on the continent, with 123 078 geo-located tweets in the fourth quarter, while Ghana's capital Accra was the most active city in west Africa and the eighth most active on the continent, with 78 575 tweets in the fourth quarter.
Portland's second study of tweeting in Africa goes deeper than its first (2011) study, looking at factors such as which cities are the most active, which languages are used the most and what issues are driving the conversations - resulting in "the first ever comprehensive map of Twitter traffic across the continent".
The study finds interesting differences with Twitter use in Europe and North America, where tweeters are largely by older adults in their thirties. "In Africa its adoption has been driven here by a younger audience, with 60% of those posting messages in their twenties," Beatrice Karanja, head of Portland Nairobi, writes on the company's website.
"African Tweeters are also are far more likely to use their mobile phones, rather than computers, to post and read messages," Karanja says, adding: "Given the explosion in mobile usage across the continent, and the increasing availability and falling price of internet-ready devices, this makes it all the more likely that [Africa's] Twitter revolution has only just begun."
More African Twitter facts
Other findings of the study include the following:
Eighty-one percent of African users tweet to converse with friends; 68% to monitor the news.
The day of Nelson Mandela's death - 5 December - saw the highest volume of geo-located tweets in Africa during the fourth quarter.
Tuesdays and Fridays are the most active tweeting days on the continent. Twitter activity rises steadily through the afternoon and evening, with peak volumes at around 10pm.
English, French and Arabic are the most common languages on Twitter in Africa, accounting for 75.5% of the tweets analysed. Zulu, Swahili, Afrikaans, Xhosa and Portuguese are the next most commonly tweeted languages.
Football is the most-discussed topic on Twitter in Africa. During the fourth quarter of 2013, football was discussed more than any other topic, including the death of Nelson Mandela. The most mentioned football team was Johannesburg-based Orlando Pirates (#BlackisBack, #PrayForOrlandPirates, #OperationFillOrlandoStadium).
Politically-related hashtags were more limited than other issues, with only four particularly active hashtags tracked during the three-month period. This included #KenyaAt50 - the celebration of Kenya's independence - and the competing #SickAt50.