Facebook remains the undisputed king of social networks. If you’re sharing your stories or looking for sources, your time is well spent there.

But if you want to keep up and catch up with your audience, you can’t be only there, especially as the web moves to an ever more-visually driven medium. (And no, “But I’m on Twitter, too” isn’t enough these days.)

A study out this month finds that the clear winner in growth is another Facebook-acquired property is gaining on its photo-sharing corporate cousin: Instagram. According to research firm GlobalWebIndex, whose quarterly social summary (for Q4 2013) released this month pegs Instagram as the fastest growing — by a long shot — social network.

According to their survey, Instagram grew a whopping 23% in active usage in the fourth quarter of 2013. That same period saw a 3% decrease in Facebook’s usage, as well as in YouTube. To be fair, Facebook is still the most trafficked network, and with far more users already signed on it has less room to grow, but other budding social networks are gaining on it. Read more