Evidently the Google+ honeymoon is over, and it’s time to start focusing on fundamental Facebook features again
Messenger lets groups of Facebook users communicate with one another in the moment even if they're using different communication technologies—for example, with one person using instant messaging, another text, and a third e-mail. Messenger taps into Facebook's vast supply of data about contacts and connections, including users' e-mail addresses, instant-message handles, and phone numbers.
Facebook already offers a feature called Groups, which lets people communicate over time about specific topics of interest, and one called Events, which lets them plan social occasions. But these aren't much good when groups want to communicate on the spur of the moment. "Until recently, you couldn't do it in real time," says Lucy Zhang, one of the engineers who built Messenger. Zhang is a cofounder of Beluga, a startup that created group-messaging tools and that was acquired by Facebook in March. Beluga's technology became the core of Messenger.