Facebook Messenger has 700 million monthly users, and each of them them requires an accompanying Facebook account. Today, however, that changes.
Facebook has removed the need to have a Facebook account, or for that matter an email address, to sign up for its messaging service. Now, on the Messenger welcome screen, users will see a new “Not On Facebook?” button where you can submit your name and a valid phone number.
On the company blog, Facebook notes, “With this update, more people can enjoy all the features that are available on Messenger — including photos, videos, group chats, voice and video calling, stickers and more.” The signup process is now identical to another Facebook-owned messaging service, WhatsApp, which authenticates using a phone number.
Facebook has first opened this up to those located in Canada, US, Peru and Venezuela.
[source] Facebook [/source]