evite etiquette: reply now
People sometimes ask me if they have to reply to their Evite invitations. Well, yeah.
Look at it from the host's perspective. They want an accurate headcount so they can get enough food, drink and space for everybody. And nobody likes to open their Evite invitations and see names in the "not yet replied" section. It's depressing, and it's a good way to get yourself disinvited from future parties.
And speaking of the host's perspective...they can totally see the date you last viewed the invitation, so don't make them bust you on it. Just take the 2 seconds to go to the invitation and reply. And no, you don't have to include a clever comment, but it would be nice if you did.