Aug 23, 2011 16:31 GMT  ·  By

If there were any more doubts that Facebook is a global phenomenon, you only need to look at the most popular countries on the site, i.e. the ones with most users, to see the clear trend.

The US sits at the top, of course, but below it sit several big and mostly understated countries which have tens of millions of Facebook users.

And the trend is accelerating, as Turkey has now overtaken the UK, one of the places outside of the US where Facebook was very popular early on, to claim the fourth spot, according to data from Socialbakers.com.

Turkey is a big country, no doubt, but even so, Facebook is now used by the big majority of internet users, in the country, 85.58 percent. Overall, 38.5 percent of the population has a Facebook account.

What's really interesting is that Facebook is rapidly reaching saturation in the emerging countries as well, after doing so in places like the US and the UK a few years back.

Other places where Facebook is big are Indonesia and India. Indonesia, with 39.5 million Facebook users, is the second largest country on the site. And the site's popularity has been rising in the country constantly.

The same is true in India, where 33.5 million people use the social network. India was actually one of the last places where Google's Orkut was popular and Facebook only recently managed to overtake it.

This means that there's plenty of room to grow here as well. Even more so, as only 41 percent of the country's online population is using Facebook.

Granted, the US, with 154 million users will remain Facebook's biggest market for some time to come. Advertising revenue is also significantly smaller from these emerging countries. But the amounts can only grow and Facebook is set to dominate the global ad world, or at least grab a big portion of it in the coming years.