We are thinking about forgoing the RSVP card in the invitations. We feel that most people are going to use the RSVP on our website and that we can save a lot of postage and printing if we send the invites with a card that says to RSVP online at our website instead of including all of those cards and paying all that return postage that I'm afraid won't even get used. Is this super tacky or a bad idea?