Facebook (FB) recently crossed 2 billion users, and India may be home to many of its next billion.

The country has long been a growing market for the social media network as more Indians come online. However, based on new data sent to advertisers, Facebook now has 241 million active users in India – a million more than it does in the U.S.– making India the country with its largest user base for the first time. The report from The Next Web also noted that active users in India have increased 27% during the last six months compared to 12% in the United States.

Source: TNW/Hootsuite/We Are Social

While the social media network operator is already enjoying double-digit growth in one of the world’s most populous nations, social media penetration in India is still less compared to other countries, representing a big opportunity for Facebook. According to the report, 19% of India’s population uses the platform compared to 73% in the United States. The average around the world is 42%. Rounding out the top five countries with the most active daily users in July were the U.S., Brazil, Indonesia and Mexico. Breaking it down by city, Bangkok led the pack with 35 million users, with Jakarta, Dhaka, Mexico City, and Istanbul all making it into the top five. India's New Delhi was at No. 6. (See also: Facebook's New Mission Moves Focus to Groups)

Late last month Facebook announced it has more than 2 billion users who post or trawl the social network at least once a month. But that impressive growth—it took it less than five years to grow from 1 billion monthly users to 2 billion—comes with a catch. Acquiring the next billion will mean it needs to grow in markets including ones it is blocked in, namely China. The social media company is the undisputed leader around the globe, particularly in the developed world, but there is still around 15% of people that have no access to it or the internet. What’s more, while 3 billion people are using the internet, around 700 million of them are located in China, a country Facebook has been shut out of since 2009. (See more: Facebook Hits 2B Users: Will China Get It to 3B?)

India can also help Facebook hit the 3 billion mark given the rosy projections for its future in the country. eMarketer, the research firm, is forecasting 182.9 million people will access the platform on a regular basis this year. That amounts to 69.9% of social network users in the country and 42.6% of Internet users. That is expected to increase to 70.1% by 2021.

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