The new way of doing wedding invitations seems to be email out a link to a website which you click on to RSVP.
Fine.
However the last few I've received haven't had "Dear " so I don't know who is invited or who I am RSVPing for!
I've received one today where to rsvp you have to search for your name and click on it when it comes up in the search results. I already knew it was child free so haven't bothered searching for my kids' names but have just spent 10 mins searching for my DH's name (in every spelling iteration, shortening/lengthening of it can think of). Finally I've come to the conclusion he isn't invited (which is fine, it's their wedding, even if all 8 of your family came to mine a few years ago...)
Anyway the point is, wouldn't it be a lot easier for everyone if you had written the invitee's names on the invitation!