Facebook
fb
This is easily the largest social networking site in the world and one of the most widely used. And, Facebook was perhaps the first that surpassed the landmark of 1 billion user accounts.
Apart from the ability to network with friends and relatives, you can also access different Facebook apps to sell online and you can even market or promote your business, brand and products by using paid Facebook ads.
Recently Facebook has lost the trust of millions of its users by allowing 3rd parties to access over 87 million users’ personal data. This is a massive breech of trust and has created a feeling of unrest amongst the social media platform’s audience. So much so that there is now a #deletefacebook campaign where people are completely removing themselves from Facebook and using other networks instead. If you’re concerned about what Facebook is doing with your data, then why not check out my guide on alternatives to Facebook, and see if there’s a better place for you to interact with family and friends.
Number of active users per month: 1.59 billion approximately

WhatsApp
Despite having been acquired by Facebook in 2014, this instant messaging platform exists as an independent entity.
It arrived on the scene much later than Facebook, but has been able to capture the imagination of millions of people across the world by giving them the ability to communicate and share instantly with individuals and groups. The WhatsApp call feature is just the icing on the cake!
Number of active users per month: 1 billion approximately

qq
Tencent QQ (more popularly known as QQ) is an instant messaging (chat-based) social media platform. It became international (with more than 80 countries using it), after it was launched in China.
It can be used to stay in touch with friends through texts, video calls and voice chats. It even has a built-in translator to translate your chats. To find out more, head over to our Chinese Social Media stats page.
Number of active users per month: 853 million approximately

wechat
This is an all-in-one communications app for messaging and calling (similar to WhatsApp) that enables you to connect with the people of your choice. It was also developed by Tencent in China and can easily work alongside QQ. As per the BI intelligence report, the number of WeChat users are fast catching up with the number of WhatsApp users.
Related article: WeChat keyboard shortcuts
Number of active users per month: 697 million approximately

Qzone
Like QQ and WeChat, QZone is yet another social networking service developed by Tencent. It enables you to share photos, watch videos, listen to songs, write blogs, maintain diaries and so on. It also empowers you to choose the accessories and customize the look and feel of your QZone webpages.
Number of active users per month: 640 million approximately