Facebook opened up Messenger to users without a Facebook account. Source: Facebook.

It's hard to imagine a world where Facebook (META 2.26%) isn't the most popular social network. With 1.44 billion users and growing, its ubiquity is a huge part of its value. Still, there are some countries where Facebook isn't nearly as popular as the rest of the world.

Facebook knows this, and it has shown off its strategic aptitude with the purchase of WhatsApp and Oculus and the separation of Messenger from the Facebook mothership. Both of these properties should enable Facebook to have a presence in countries where its social network is less popular.

Without further adieu, the three countries where Facebook is least popular.

China (~0% use Facebook)
Facebook is banned in China, whose government censors the Internet. Domestic companies dominate the Internet landscape in the country, with Tencent (TCEHY 2.25%) leading the way.

Tencent's Qzone had 668 million monthly active users as of the end of the first quarter, with 568 million on mobile. That's practically all of the Internet users in China. Tencent has found international success with WeChat (known as Weixin in China), which has 549 million active users globally, with the vast majority inside China.

Facebook has added several features to Messenger based on WeChat, which has successfully started monetizing its users. Messenger's payments, voice recording, stickers, and location sharing all have roots in WeChat. Facebook will have to come up with ideas of its own if it wants to gain a foothold in messaging in China. WhatsApp is no help, either. Estimates are that just 23 million Chinese use WhatsApp.

Facebook could get its foot in the door through the Oculus Rift, which it plans to release in China. Another option is to develop apps tailored for the Chinese audience, which has developed its own taste compared with the rest of the world.

Japan (39% use Facebook)
Twitter (TWTR) has become the most popular social network in Japan. The mobile-first, short-form, relatively anonymous social network fits well within Japanese culture that values privacy and can say a lot more in 140 characters than English speakers.

Facebook, however, is gaining popularity in the country, but Japanese use the social network the way Americans might use LinkedIn. Because of Facebook's real-name policy, users are compelled to display themselves more professionally.

This behavior opens up a door to market a separate Messenger from Facebook, so that more users can communicate with professional contacts and keep their personal and professional lives separate.

Russia (67% use Facebook)
By the time we get to the third least popular country, the powerhouse that is Facebook already starts to show its strength. Even in a country where Facebook faces strong competition from domestic player VK (formerly VKontakte), it still manages to attract 67% of Internet users to its platform. For reference, about 80% of Americans use Facebook.

The political environment in the country has led Facebook to censor certain content on its website in Russia. VK, on the other hand, saw its founder and CEO pushed out, to be replaced by managers more aligned with President Putin.

Messaging apps may continue to play an important role in Russia's social-media environment, since publicly posted content could get censored. WhatsApp has a moderate presence in the country, and opening up Messenger could give Facebook another horse in the race in one of the fastest-growing Internet populations in Europe.

Can't please everyone
Despite its immense popularity, Facebook simply can't be everything to everyone. That's why owning a wide-ranging portfolio of apps and services is important for the company to grow its presence throughout the world. Oculus may give it an in with China; Messenger could prove valuable as a stand-alone app in Japan; WhatsApp could boost Facebook's presence in Russia.

Facebook continues to invest in several different verticals, many of which have universal appeal. But expecting all of them to be popular everywhere is unreasonable. Instead, Facebook can use its smaller apps and platforms to compete with the local players in a diverse range of markets.