This week in social media, Pew Research released a new survey on social media use in the U.S. The research found that while Facebook far outweighs other social media networks, at the same time, it showed little growth compared to the rest.

It's time for Social Media Saturday!

Facebook: Big, But Slowing

Facebook has been the heavy-hitter in social media for years now. But it may not be that way years from now, if trends continue along the way they're going, according to Pew Research's social media study, released this week.

Based on the 81 percent of American adults who use the Internet, Pew found that 71 percent of them use Facebook. That's quite impressive, compared to the competition, which got marks in the mid to high 20th percentile.

But the bigger takeaway is that Facebook had about the same level of popularity at the same time last year, scoring an identical 71 percent on Pew's social media charts, and that's just four percent up from the previous year.

You might say we've reached peak Facebook, and now people are beginning to diversify their social media use into other platforms.

LinkedIn, Pinterest, and Instagram More Popular

In fact, Pew tracked the diversification of social media use in its survey, finding that 52 percent of online adults now use two or more social media sites, a rise in ten percent from last year.

This is reflected in the numbers for LinkedIn, Pinterest and (Facebook-owned) Instagram, which all showed significant gains over the past year, with the first two gaining momentum and passing a quarter share of the social media market.

Pew found that, in regard to LinkedIn's popularity, Internet users with college educations took to the social network for the first time this year at a particularly high rate, with one out of every two deciding LinkedIn was important enough to their professional careers to join. The "necessity" question may explain why Facebook -- explained as the "home base" site of for many of those online -- reached a peak at 71 percent, while LinkedIn, which promises career advancement through networking, is growing at a fast clip.

Pinterest's Domination Among Women

But it doesn't explain the similarly quick rise of Pinterest, which is known mostly for shopping and sharing photos. What does explain it (at least a secondary explanation), is the fact of the image-clipping network's popularity with women: An incredible 42 percent of all online women use the platform.

More Disappointing News for Twitter

Twitter showed up in Pew's top five social media sites, but as a social media network that was once seen as the alternative and chief rival to Facebook, its fifth-place standing must be disappointing, adding to the increasingly crushing pile of failed expectations that's been accumulating throughout 2014.

The 140 character-limited network came up with only 23 percent in Pew's survey, a gain of five percent over the last year. Even more distressing for Twitter is Pew's social media matrix, in which the research center crossreferenced the growing population of social media users who frequent more than one network at a time.

Pew's matrix found that, while 91 percent of Twitter users also frequent facebook, only 29 percent of Facebook users also participate in Twitter -- the lowest percentage of the remaining four networks.