Unlike in the past, people now aren't required to have a Facebook account to access Messenger.
The move is a way for Facebook to reach a bigger audience, attracting people who don't already have Facebook accounts and getting them to gradually use more Facebook services. In addition, it could also become a way to increase the Facebook usage of existing members by giving them a way to communicate via Facebook with friends who aren't already on the social networking site.
While most people in developed nations have email, people in emerging markets often do not. And even mature markets, like the U.S., are starting to see a shift where people, particularly teens and younger people, communicate via text or Facebook as opposed to email.
Accordingly, the new Android Messenger sign-up feature will first be available to a small number of countries -- India, Indonesia, Australia, Venezuela, and South Africa -- before being rolled out more broadly.
The company noted in a blog post that the update to Messenger is available today, and Messenger accounts will become available over the next few weeks.
Peter Deng, director of product at Facebook, today during the Le Web conference in Paris noted that Facebook has had some users specifically open email accounts so they can get access to Facebook. The new version of Messenger will allow a bigger group of people to access the program, he said.
"As a result of focusing on mobile, for the past year-and-a-half, we've been investing a lot in mobile messaging. We've noticed that people have wanted more than SMS can provide. ... We want to let people connect with each other and feel like they're in constant communication," Deng said.
While the new feature is first available only for Android, Facebook is working on versions for other operating systems, as well, including iOS, Deng said. He didn't specify when the new feature will be rolled out globally or when it will arrive on other operating systems.
However, Deng said Facebook now is on a set cadence with products, where every six weeks, it releases whatever new features are ready. He noted that Facebook Messenger has been updated about seven times in the past year.
In addition, Deng said Facebook is looking at ways to let the new sort of Facebook users -- those who don't have email and don't sign up for traditional Facebook accounts -- try other parts of the Facebook product, like photos.
"We'll get to ways of eventually letting them do that, but today, messaging is our goal No. 1," he said.
Facebook isn't just working on spreading Messenger to other smartphone operating systems. It's also focusing its efforts on allowing more feature phone users to access the program. Deng noted that every day, Facebook is accessed by about 7,000 different devices.
In India and Indonesia, some carriers are going to provide reduced rate data plans for people who just want to use Facebook Messenger, he noted.
"We recently announced 1 billion monthly active users, which is a good milestone for us," Deng said. "But a lot of people out there are not using the Web ... It's a huge, untapped potential."
Updated at 7:40 a.m. PT with additional details and comments from Facebook's Peter Deng.