Facebook sees some user benefit – maybe, by having all your key connections in one place, it could prompt you to stay in touch more often. Instagram now has a billion monthly active users, while Messenger has 1.3 billion.
The integration could also help online businesses grow their connections. It’s not clear as yet if the option will be available to business profiles on Messenger, but if it is, you could use it to merge your contacts to raise awareness of, say, your brand’s Messenger Bot or to spark a more direct conversation with your users. Under Messenger’s business rules, there are limitations on how you initiate that contact, but it may offer some new opportunities if the function extends to brand profiles.