Twitter user growth flattens out; most users are outside U.S Number of monthly active users on Twitter
Twitter’s user base has grown rapidly but may be plateauing. Twitter averaged 320 million monthly active users (MAUs) in the fourth quarter of 2015, 9.6% more than in the same quarter a year earlier, according to the company’s financial disclosure statements. That’s Twitter’s slowest annualized growth rate since at least 2011, when comparable data began to be publicly disclosed. Domestic, international and total MAUs were all flat or slightly down compared with the third quarter. (The company defines an MAU as anyone who accessed the service at least once in the past 30 days.)
Twitter is largely a global service. Twitter has nearly four times as many users internationally as in the United States – 254 million versus 65 million, as of the fourth quarter of 2015, according to company filings. However, the company says, Twitter’s penetration generally is higher in the U.S. than in other countries in which it operates. Last year, Pew Research Center estimated that 23% of all adult internet users, and a fifth of the entire adult population, uses Twitter. In the U.S., usage is highest among urban residents, adults under 50 and people in upper-income brackets.
Twitter user growth flattens out;  | most users are outside U.S  | Number of monthly active users on Twitter  | 350 million  | 300  | 250  | 200  | 254m  | International  | 150  | users  | 100  | 50  | U.S users  | 65m  | Q1  | Q1  | Q1  | Q1  | Q1  | Q1  | Q4  | 2010 2011 2012 2013  | 2014 2015 '15  | Source: Company financial reports.  | PEW RESEARCH CENTER 