Instagram's astonishing growth is set to continue for a while yet, eMarketer predicting more than 100 million monthly Instagram users by 2018.
The research firm analysed data from other researchers, government agencies, company reports and media outlets for their forecast, resulting in a figure of 106.2 million users, or 33.6% of the US population. By 2019, this is set to rise to 111.6 million, or 33.6% of the population.
Instagram already boasts 300 million global monthly users, making it bigger than Twitter, and thus the world's second-biggest social network. Twitter now trails behind with a measly 284 million, according to the BBC.
If eMarketer's predictions are correct, this gap is set to widen, with the photo sharing platform enjoying double-digit growth for the next two years. Twitter's growth is expected to slow to single digits this year.
Facebook, meanwhile, can sit comfortably as the biggest social network. According to Statista.com, Facebook had 208 million monthly active users in the US and Canada alone in Q4 2014, and 1,393 million worldwide.
Commenting on the predictions, eMarketer's Debra Aho Williamson said: "Instagram has a lot of momentum in the US, growing faster than Twitter, Pinterest, Tumblr and Facebook."
"The simplicity of the app is what is most appealing; Instagram has stayed true to its core mission—delivering beautiful imagery and videos—while other services, such as Snapchat, have loaded on lots of new features."
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