https://www.theverge.com/2018/6/20/17484420/instagram-users-one-billion-count

Instagram announced at an in-office event today that it now has 1 billion users worldwide. It had 800 million users in September of last year, which was 200 million more than that same time the year before. The app just keeps steadily adding 200 million users a year, it seems.

“It’s incredible, and it’s something Mike and I never thought would happen,” co-founder Kevin Systrom said.