At a recent all-hands meeting with employees, Kevin Systrom, a founder and chief executive of Instagram, showed off one of his favorite charts: Days to Reach the Next 100 Million Users.
“It’s the only graph in the company that we celebrate when it declines,” Mr. Systrom said in an interview last week at Instagram’s headquarters in Menlo Park, Calif.
Not long ago, the Facebook-owned photo-based social network grew at a steady clip. Every nine months, without fail, Instagram added another 100 million users somewhere in the world. Then, last year, it began racking up more new users every day. It grew to 600 million users from 500 million in only six months.
On Wednesday, just four months after reaching that milestone, the company announced it had reached another: About 700 million people now use Instagram every month, with about 400 million of them checking in daily.