About one-third of world's population, or 2.46 billion people, will view a social media site at least once a month this year, according to an eMarketer forecast. Social media use has increased 8.2% since last year, boosted by smartphone usage. Individuals in Asia-Pacific, Latin America and the Middle East and Africa are largely new Internet users who are signing up for social media for the first time. In 2017, 81.8% of social network users worldwide will log in via a mobile phone. By 2021, that share will grow to 86.7%.