Pew:

Facebook continues to be the most popular social media site, but its membership saw little change from 2013. The one notable exception is older adults: For the first time in Pew Research findings, more than half (56%) of internet users ages 65 and older use Facebook. Overall, 71% of internet users are on Facebook, a proportion that represents no change from August 2013.

Every other social media platform measured saw significant growth between 2013 and 2014. Instagram not only increased its overall user figure by nine percentage points, but also saw significant growth in almost every demographic group. LinkedIn continued to grow among groups with which it was already popular, such as professionals and college graduates, while Twitter and Pinterest saw increases in usership across a variety of demographic groups.

Pew excels at proper research in contrast to the well-described dangers of anecdotal extrapolation.