Nearly 1 billion Facebook users worldwide will access the social network on a mobile phone at least once each month in 2015, according to a new forecast from eMarketer, which for the first time breaks out mobile phone Facebook users by country.

Over 70% of all Facebook users globally will be mobile this year, and by 2018, more than three-quarters of the social network’s audience will access the platform via mobile phones on a regular basis, totaling 1.34 billion users.
It’s no secret that mobile has been the key driver of growth in Facebook’s advertising business in the past 12 months. In 2013, 45.0% of Facebook’s $6.99 billion in advertising revenues worldwide came via mobile ads. This year, mobile ads will account for 73.0%—or $10.90 billion—of the social network’s ad revenues worldwide, eMarketer estimates.

“Facebook has been a leader helping marketers to transition to mobile advertising,” said Debra Aho Williamson, principal analyst at eMarketer. “Because the Facebook experience is basically the same across devices, advertisers don’t have to reinvent the wheel to place mobile advertising. As Facebook’s user base shifts even more heavily toward mobile, it is well positioned to see increasing ad revenues from this channel.”
Overall, there will be 1.58 billion mobile phone social network users worldwide in 2015, according to eMarketer. Even considering the ban in China and strong local social networks in other large-population countries like Russia, mobile Facebook users will still represent more than 60% of the worldwide mobile social audience.
The US will remain the largest market for mobile phone Facebook users this year, and nearly 80% of users in the country, or 123.1 million people, will access the site regularly via mobile phones. Mobile ads will account for 74.0% of the company’s ad revenues stateside, eMarketer estimates, slightly higher than its share on a worldwide basis.

India—the world’s second-largest Facebook audience—will surpass 100 million mobile phone Facebook users for the first time this year, and by 2017, will have more mobile Facebook users than the US. The third-largest mobile phone Facebook audience is in Indonesia, which also has the highest penetration among the top 10 countries in terms of mobile phone Facebook users—92.4% of Facebook’s audience there accesses the network from mobile phones at least once per month. By 2018, that penetration will rise to 98.8%. The UK and Russia are the only other countries in the top 10 where mobile phone Facebook users will account for more than 90% of all Facebook users during our forecast period.
eMarketer bases all of its forecasts on a multipronged approach that focuses on both worldwide and local trends in the economy, technology and population, along with company-, product-, country- and demographic-specific trends, and trends in specific consumer behaviors. We analyze quantitative and qualitative data from a variety of research firms, government agencies, media outlets and company reports, weighting each piece of information based on methodology and soundness.
In addition, every element of each eMarketer forecast fits within the larger matrix of all its forecasts, with the same assumptions and general framework used to project figures in a wide variety of areas. Regular re-evaluation of each forecast means those assumptions and framework are constantly updated to reflect new market developments and other trends.