[JohnFen]

I have two thoughts about that. First, reliability -- are you certain that everyone you'd send such an invite to would receive them? That they wouldn't get sucked into spam folders? That everyone checks their email regularly?

The other is that paper invitations are just nicer overall. They give a feeling of permanence, are classier, give your loved ones a memento (or at least something to stick on their fridge for a while), etc.

Electronic invitations seem to me to be more emotionally distant, less "real". More suitable for ephemeral, relatively unimportant events.