The microblogging service will continue to invest and hire in Japan and will also add engineers, Costolo told reporters in Tokyo today, without specifying investment amounts or the number of people being added.
The San Francisco-based company, which lets users post 140- character messages, is expanding abroad to decrease its reliance on the U.S. market. The percentage of revenue Twitter earns from the U.S. will fall to 83 percent in 2014 from about 90 percent this year, researcher EMarketer estimated in January.
Japan had the third-largest share of Twitter users with 29.9 million accounts created before Jan. 1, according to Semiocast, a social-media research company. The U.S. had 107.7 million accounts and Brazil had 33.3 million, according to the Paris-based researcher. Japanese was the most-used language on Twitter after English, Semiocast said.
Twitter has 140 million active users globally, Costolo said.
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