[detaro]

Hadn't thought about that aspect, but that's of course right: a random mail address only gives you a way to contact someone, but not other context.

It's great if you have something specific you want to follow up on, otherwise it just gets filed away. Or can be used to give Facebook/Twitter/whatever else information the next day if you want to (after thinking about it). Mail addresses can be more anonymous and easier to dispose in that way, if you have clearly separated ones.