Gettyimages Social Networks
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Social network apps and websites have consumed the internet. Facebook (NASDAQ:FB) boasts that its users spend an average of 50 minutes per day between Facebook, Instagram, and Messenger.  And that's while competitors like Snapchat and Pinterest continue to grow and take up our time, too.

2016 saw a few notable changes in the industry. Here are the most popular social networks.

Facebook

With 1.79 billion monthly active users, Facebook is by far the largest and most popular social network in the world. In fact, it has more daily active users -- 1.18 billion -- than any other platform on this list has monthly users.

Facebook's size is one of its biggest competitive advantages and it benefits from the network effect, whereby something becomes more valuable as more people use it. If you want to connect with new or old friends and acquaintances, you go to Facebook. Its size also attracts advertisers, of which it counts 4 million.

Facebook continues to grow at a steady pace; its user count was up nearly 16% year over year in the third quarter. Last year, users increased just over 14%. There's no reason to expect Facebook's user growth to slow too much, even with 1.79 billion users already.

WeChat

WeChat ended the third quarter with 846 million users. TenCent's (NASDAQOTH:TCEHY) mobile chat app -- known as Weixin in its native China -- has quickly transformed into much more than just a way to send text messages. The company launched its Moments feature nearly four years ago, which emulates Facebook's News Feed and Wall. WeChat also supports social gaming and payments, and Chinese users can even use Weixin Wallet to pay for goods in stores.

Advertising in WeChat Moments is fueling Tencent's online advertising revenue growth. Ad revenue increased 51% in the third quarter.

WeChat's growth is outpacing almost every other social network of its size, including Facebook's more traditional messaging apps, Messenger and Facebook. Users increased 30% year over year last quarter, as it added 40 million new users in the previous three months.

QZone

WeChat isn't Tencent's only social network. Qzone is a more traditional social network in the vein of Facebook or MySpace. With 632 million users, it's one of the largest social networks in the world. User growth, though, is heading in the wrong direction. Active users declined 3% year over year in the third quarter.

Tencent monetizes QZone with games and subscriptions. "Canary Yellow Diamond" members can play third-party games at a discount compared to normal users, but they pay a monthly fee to QZone. It also uses advertising.

Combined with WeChat, QZone has fueled 58% growth in Tencent's social media revenue.

Instagram

Instagram was one of Facebook's biggest revenue growth drivers in 2016 after opening up its advertising to everyone late last year. The increased number of ads didn't deter new users from signing up, though. The photo-sharing network added 100 million new users from last September to June, reaching 500 million total.

The social network continues to experiment with ad formats, recently introducing a "shop now" button. It also introduced a new format to share content -- Stories -- that emulates Snapchat's feature by the same name.

Instagram could contribute as much as $3.2 billion to Facebook's top line in 2016, according to Credit Suisse analysts. (Facebook doesn't break out Instagram's revenue.) With an expected slowdown in ad revenue growth from its flagship platform, investors are hoping for continued growth from Instagram going forward.

Snapchat

Snapchat is quickly climbing the list of most popular social networks. The photo-messaging app has quickly expanded its feature set to become one of the most often-used apps on people's phones. While it doesn't report exact metrics, it has over 150 million daily active users, according to Bloomberg. That's more than analysts' estimates for Twitter.

Snapchat is also developing new ad products and new targeting capabilities for Snapchat, which has led to some lofty growth expectations. Internal growth expectations have the company producing as much as $1 billion next year. That number is backed up by estimates from eMarketer, which project $935 million in revenue next year and $1.76 billion in 2018.

Twitter

Twitter's (NYSE:TWTR) struggles got real in 2016. Jack Dorsey took over as permanent CEO late last year, but he's been unable to turn around the company's sluggish user growth. With 317 million monthly active users, its user count has climbed just 3% year over year.

The lack of user growth is finally starting to weigh on the company's revenue growth. After just 8% growth in the third quarter, analysts are projecting just 4% growth in the fourth quarter. Twitter faces intense competition for ad dollars from faster-growing and more engaging social networks like Snapchat, Instagram, and Facebook.

While Twitter is still relatively popular (317 million users is nothing to sneeze at), its lack of growth is troubling.

Plenty more out there

There are dozens of other social networks on the web from all different countries. There's Weibo (NASDAQ: WB), the Twitter of China, with 282 million monthly active users and growing strong. It might not be long before it overtakes the social network it's modeled on.

There's also Pinterest, which recently announced surpassing 150 million active users. It has a strong hold on the social shopping advertising market, and it's working to fend off other photo-centric social networks like Instagram.

There's LinkedIn (NYSE: LNKD), which counts 106 million monthly visitors and 467 million total members. The professional network has more diverse revenue sources compared to competitors with premium subscriptions, and its talent solutions segment contributes most of its revenue. Microsoft (NASDAQ: MSFT) has agreed to acquire the company and plans to integrate it with its Office productivity software suite.

The list goes on, but that rounds out the most popular social networks of 2016. With social networks and apps taking up more and more of our time, these are some of the most interesting companies to pay attention to in the internet space.

Adam Levy has no position in any stocks mentioned. The Motley Fool owns shares of and recommends Facebook and Twitter. The Motley Fool owns shares of LinkedIn and Microsoft. The Motley Fool recommends Weibo. Try any of our Foolish newsletter services free for 30 days. We Fools may not all hold the same opinions, but we all believe that considering a diverse range of insights makes us better investors. The Motley Fool has a disclosure policy.