Just a few months after Facebook stopped allowing messaging in its main iPhone and Android apps, forcing users worldwide to download a separate, standalone app dubbed Messenger, the company is sharing its user numbers.

The social network has revealed that over 500 million people are now using the Messenger app each month. This compares to Whatsapp, the popular messaging service Facebook acquired back in February this year for a whopping $19 billion, which has nearly 600 million active monthly users.

"This is an exciting milestone but with a half billion people relying on Messenger to communicate and connect, it is also a reminder that there is so much left for us to do", said Peter Martinazzi, Facebook's director of product management.

Facebook didn't reveal platform-specific numbers, so it isn't yet known how many of the Messenger users are on Android, iOS, and Windows Phone. As for what features are in the pipeline, the company just said that the app will continue to "evolve and improve".

The Messenger app, which has existed since 2011, currently doesn't make any significant money for Facebook, but that could change in future, given that the company recently hired PayPal CEO David Marcus as head of its "Messaging Products".

With Marcus leading the efforts, there are speculations that payments could be the key to earning money, rather than ads. Back in April, the company applied for an e-money license in Ireland.

Facebook currently has around 1.35 billion monthly active users, and the company hopes to scale Messenger up to similar numbers. "We're going for a billion", Marcus told Wired. You can download Facebook Messenger for all platforms here.