Ask David Marcus, Facebook’s VP of Messaging Products, which new feature Messenger users want the most, and it’s no contest: group video chat.

“It’s hard to argue group video chat isn’t the next logical step,” the Facebook (FB) executive acknowledged to Yahoo Finance this week.

That follows on the heels of Messenger announcing that over 300 million people now make audio and video calls inside the Messenger app each and every month.

It’s another impressive milestone for Marcus, who recently hit the two-year mark at Facebook following a stint as president of PayPal (PYPL) and CEO of Zong, the mobile payments provider PayPal acquired in 2011 for a reported $240 million in cash.

Since joining the social network to run Messenger, Marcus has expanded the group to about 250 employees and evolved Messenger into a wide-ranging messaging platform that lets users send payments to one another and interact with businesses via bots.

The platform also allows outside developers to augment the Messenger experiences with touches like stickers and animated GIFs.

“We needed more users, and we needed to drive more engagement and drive reach, so that was really the focus,” Marcus admitted. “It was a matter of figuring out, how do we build a product that people want to use everyday? To make it dependable. To make it fast. To make it reliable.”

The results speak for themselves: When Marcus joined, Messenger had fewer than 300 million users. Just two years later, over 1 billion users now message, call or send stickers to one another each and every month.

The path to 1 billion users hasn’t been smooth. Some Facebook users hate change — that’s just fact. Roll out a revamped News Feed or tinker too much with privacy settings, and a subset of users cry foul. Such was the case when Facebook made its Messenger app a mandatory download in summer 2014.

Since then, however, the hubbub has mostly subsided, giving way to rapid user growth as more and more Facebook users warmed to the feature-packed Messenger app.

Marcus says businesses also remain enthusiastic about having a presence on Messenger.

Love them or loathe them, 30,000 bots now run on Messenger, letting users scout for apartments online via Trulia (TRLA) or consult health professionals with HealthTap. For now, businesses do not pay Facebook for bots on Messenger, but do offer News Feed ads, where developers buy ads that appear in the News Feed. If a user clicks on those ads, they’re shuttled inside Messenger to interact with that business’s bot.

Marcus also points to businesses such as Match.com’s (MTCH) UK arm Meetic, which has built a dating bot named “Laura” inside Messenger that serves up potential dates based on their search criteria. The Facebook executive says Meetic is seeing twice the number of users convert to paid subscriptions on Messenger versus downloading the standard Meetic app or being redirected to Meetic’s mobile website.