WhatsApp is now officially Facebook’s most popular service in India.

At a media event Tuesday to announce the new video calling feature, WhatsApp said its instant messaging and voice calling service is being used by 160 million active users every month in India, its biggest market. In contrast, Facebook had 155 million monthly active users in India as of late last month. WhatsApp hit one billion monthly active users worldwide earlier this year.

It doesn't come as a surprise that so many people in India are using WhatsApp. Whether you're looking for a plumber, or going to a fish market in India, WhatsaApp has become ubiquitous in the country. Even government organisations such as police departments are using WhatsApp, and so are teachers who are using this instant platform to swiftly connect with students.

WhatsApp has been particularly successful in India because of its cross-platform availability and relevance to the local market. At the time WhatsApp entered India, people were mostly using traditional SMSs to communicate with people. Unlike Western nations, ISPs in India didn't offer texts for free. This got WhatsApp an instant foothold in the country.

Neeraj Arora, VP of WhatsApp, said the company truly cares about Indian audience, adding that WhatsApp can be used in more than 10 local Indian languages.