I was thinking about not sending RSVP cards with an invitation and instead writing "please rsvp on our website". I want to save on postage + paper! Is that tacky? I'm afraid the guests who are older will think so, since it isn't "normal".
Also, for anyone who has done this, can your guests search names of other guests? That is one thing that worries me!! That sounds like a disaster waiting to happen, ha!