It's been just a bit over a year since Instagram launched its Android app and Facebook announced plans to buy the photo-sharing service — and in that year, Instagram has added some 90 million users, for a grand total of 130 million active users each month. To say that growth has Instagram CEO Kevin Systrom positively bullish about the future of his service would be a bit of an understatement. Fast Company recently sat down with Systrom and asked if he thought Instagram's growth meant that his service could someday outstrip Facebook in terms of users, and from his response it sounds like Systrom is looking even beyond that milestone. "By definition, if it keeps growing at this rate, yes, it will be bigger [than Facebook]," Systrom said. "It will be the biggest thing in the world."

It's quite a confident response, and there's no doubt the company has had a huge year — but despite that year of growthj, Instagram is still much smaller than Facebook and will always have a smaller feature set. Systrom did quickly pull things back a bit, saying "will we continue to grow at this rate [and outgrow Facebook]? Different question." His fellow co-founder Mike Krieger was asked the same question and had a bit more of a diplomatic response. "I don't know — that's a good question. I think both of them are basically limitless in size, so maybe one day they'll be the same size?"