The folks at Adweek created an infographic (based on eMarketer's US Digital Media Usage report) that illustrates how the social media landscape will change in 2015 and beyond.
According to Debra Aho Williamson - eMarketer's principal analyst:
"More than half the U.S. population uses social networks regularly, and Facebook continues to lead the market. But pay attention to mobile social networking, where Twitter, Instagram, Pinterest and Tumblr are all significant players. That's where the next phase of growth is happening."
Take a peek at below chart for more insights.