Why Facebook messaging will be a gmail killer after all

Today Facebook announced a new messaging platform. I see a lot of cynic reviews. All this reviews are blinded by the idea that Facebook was to announce a Gmail killer. I think one aspect is overlooked; the changing messaging behaviour of new generations.

Of course seen by the bare functionalities the messaging platform does not offer new functionality above combinations of Gmail and Google Talk.
But what is really different is the context of messaging. Tnis new platforms sits in a social context, a place where you are communicating in realtime with friends, putting up to speed with the lifes of people you follow. There you need sometimes different levels of communication. Just like DM in Twitter is a strong communiciation channel.

I believe that a Facebook messaging platform can take an important role in our day-to-day communication with friends. It will be therefor more a competitor for DM, chat and ping, text/sms than it will be for gmail.
But if your are honest, do you know how hard it is to reach the millenial with email?

Update: I just watched this video of Facebook explaining the system. With somewhat more focus on the messaging make easy, but I still think the social realtime context is the strongest element.