ImageIt will take a decade for Twitter to reach 1 billion users, studies show, by which point Facebook could have double, or even triple, that number.

Twitter has just reached 200 million monthly active users, cementing its place as the second biggest social networking site after the 1 billion strong Facebook. However, at its current growth rate, Twitter may never equal Facebook’s population figures.

Twitter has grown its membership figures by 60 million since March, the last time it shared its membership data registering 140 million monthly active users, an increase of almost 50%.

The increase of 60 million users in just 9 months equates to roughly 6.6 million users a month, meaning that if the increase were to continue at the same rate, Twitter would be gaining roughly 80 million new users a year.

So, even if Twitter’s user base were to grow at a steady rate, it would take a decade for them to reach the 1 billion mark, as Facebook did in October.

Facebook has been active for 8 years, that’s two years longer than Twitter, and yet it has still managed to quintuple its main rivals membership figures. Facebook also continues to grow, so even if Twitter were to reach 1 billion users within a decade, Facebook would have most probably increased their user base even further.

It took Facebook 3.5 years to grow from 200 million to 1 billion users, an increase of around 230 million users a year. If their growth rate continues, by the time Twitter has reached 1 billion users, Facebook will have surpassed 3 billion!

Of course, that is a big “if”, especially considering that of the estimated 7 billion people living in the world today 35% use the internet, roughly 2.4 billion, and that isn’t even taking into account the fact that Facebook is blocked in China, the most populous country in the world, with 22% of the world’s internet users.

So, according to these figures, 2 billion of the world’s internet users have access to Facebook, while 1 billion use it.

The UN estimates that by 2020, the world population will be 7.675 billion, an increase of 675 million from 2012. in 2011, The International Telecommunications Union estimated that the percentage of people using the internet almost doubled from 2006 to 2011, 18% to 35%, while the world population increased by half a billion.

In 2010, the National Science Foundation reportedly estimated that there would be 5 billion internet users worldwide by 2020. If the percentage of internet users were to increase at the same rate of 17% every 5 years, then by 2022, 69% of the 7.675 billion people living would have internet access, meaning roughly 5.2 billion internet users.

A half of the 2 billion of internet users with access to Facebook use it. Taking Chinese censorship into account, and estimating that China will have roughly 20% of the world’s internet users in 2022, as they do now, if Facebook was to count half of the world population with access to it as members in 2022, then it would have about 2 billion users.

This is, however, presuming that Facebook remains banned in China and remains uncensored elsewhere, with internet censorship a hot topic at the moment in the UN.

That is not to say that Twitter will not accelerate its membership growth. After all, both competing sites provide vastly different services, meaning both can exist simultaneously. In fact, it is by attempting to provide a different service that the companies are directly competing: Twitter reportedly attempted to purchase Instagram for $525 million before Facebook swept in and bought the photo-sharing service for $1 billion.

Twitter cannot currently compete with Facebook financially, and they are far from achieving Facebook’s 1 billion user mark. They could, however, earn $1 billion in US-based mobile advertising revenue in 2013, thereby beating Facebook, according to a report by emarketer.

“Twitter will earn $116.8 million in mobile advertising revenues this year in the US, eMarketer projects. Facebook, which rolled out mobile ads for the first time this year, will come in at just over half that amount, at $72.7 million in the US.”

However many years it will take Twitter to reach the 1 billion membership mark, it is highly unlikely that it will ever surpass Facebook. In mobile marketing revenues, however, Twitter is leading the way.