[duaneb]

> If your user auths with Facebook, of course it makes sense to do your customer communication via Facebook, too.

Authentication is not a declaration of preferences. Who wants to do any business communication over facebook? It's straight up terrible compared to, say, email.

[icebraining]

In my anecdotal experience, a large share of the 16-20 year old crowd can barely remember their email address, let alone the password to it. They use it as much as I use my postal box.

You're still right that authentication doesn't imply authorization to send PMs, by the way.

[TeMPOraL]

It's a strange spectrum we now have in terms of business communication. The older population prefers to simply call you. The youngest population seems to prefer IMs or social media based communication (like company Facebook pages). The middle prefers e-mails.