Whatever type of event, first impressions are everything. Have you ever attended a meeting/conference/party/insert your bad experience here and had such an unpleasant experience while trying to check-in that it influenced your impression of the entire day and possibly the company hosting the program?
Consider who you have greeting guests at your next function. Are they pleasant? Can they work under pressure? Do they understand who the attendees are and the purpose of the event? Are the event hosts (Company President? Managing Partner?) greeting guests soon after they arrive?
How does the way that you greet guests at a marketing event differ from the impression that people get when arriving at your place of business?
Seth Godin reflects on first impressions after recent and quite ironic experience he had with a receptionist.
I've seen a recent trend at companies where they have a sign on the receptionist's desk that say "Director of First Impressions." I sometimes wonder if they receptionist knows that the sign is there.