The number of US Instagram users increased nearly 60 percent in 2014, bringing the social network’s US monthly user base to 64.2 million people, according to new figures from eMarketer.
Instagram surpassed Twitter to become the second-largest social network in the US. Twitter’s US user base was 48.4 million in 2014, eMarketer estimates.
By 2018, Instagram is expected to have more than100 million users.
Teens and millennials dominate Instagram’s user base. In 2015, 20.3 million US Instagram users–26.2 percent of the total–will fall within the 25-to-34 age group. for the 12-to-17 age group, 61.9 percent will use Instagram this year.