It looked like Instagram might lose some of its advertising business earlier this year. However, it appears that prediction was a bit premature, as a new eMarketer report shows that it seems to be moving along just fine.

The social media channel will see steady traffic from consumers, with 89.4 million Americans logging into the site at least once a month, about a third of all mobile phone users. That will grow even further next year, as it’s expected to jump up to 51.8 percent of all social network users, pushing it past the 50 percent mark for the first time.

Instagram is expected to grow just over 15 percent in 2016. That will end up being nearly 27 million users in four years, which is double the users expected for Twitter and bigger than most social media sites available.

Millennials are still flocking to the service like crazy, with 48.2 million expected to join Instagram this year. However, the number will blossom even more by 2019, as two-thirds of all millennial smartphone users are likely to use the platform in one form or another.

“Instagram and its parent company, Facebook, know that mobile has changed the way people — especially millennials and Gen X-ers — communicate, share and get information,” said eMarketer principal analyst Debra Aho Williamson. “That’s why they are leading the way in helping marketers reach this audience.”

A good chunk of that business will come from mobile. Around 9.5 percent of Facebook’s worldwide mobile ad revenues (20.1 percent for the U.S.) will come from Instagram alone, which will grow to 14 percent worldwide (and 28 percent in the U.S.) by next year.

“Instagram has a lot of momentum with advertisers, and its revenue is increasing rapidly,” said Williamson. “For marketers that want to target mobile millennials, Instagram is an attractive option.”