eMarketer: Twitter user base in the U.S. is beginning to mature

Growth outpacing younger user groups

The change in growth patterns indicates changes in Twitter's future. In the United States, the site has passed the early adoption mark and is adapting to a more mature user base. By 2016, more than 25% of Internet users aged 12-44 will use Twitter at least once a month, according to the latest figures from eMarketer.

eMarketer's estimate of Twitter's 2014 U.S. user base has increased to 48.2 million, up from a November 2013 pre-IPO forecast of 41.6 million. This growth reflects the company's user data released at the time and new customers it won in the fourth quarter of 2013 after it announced its IPO. However, eMarketer has also lowered its growth rate through 2018 because of the short-term user growth. Overall U.S. Twitter user growth will fall below 10% in 2015 and slow to 6.4% by 2018.

Twitter's future value depends not only on its number of users, but also on how much users engage with its ads, and older users seem to be more willing to do so. As for concerns about teens using Facebook (or not), Internet users aged 12-19 currently have and will continue to have the second highest penetration rate for Facebook, second only to the 18-24 age group.

That's not the case with Twitter. In percentage terms, 25-34 year olds are more engaged with the service than teens, with 10.4 million 25-34 year olds in 2014 and 5.5 million teens. By 2018, 35-44 year olds had almost caught up with teens, at 29.1% and teens at 29.7%. On Facebook, teens now outnumber 35-44 year olds by nearly 15% in monthly usage, and eMarketer predicts that gap will remain stable over the next four years.

A mature user base means faster growth for Twitter in the U.S., which addresses market concerns that Twitter did not grow fast enough following its recent IPO. A mature user base can also be a relatively stable user base. Twitter's mature user base not only in terms of number but also in terms of age will affect its advertising revenue potential.