When you announce what the event is and welcome people, they feel "part of the group" as as individuals sometimes we like a little association. Thus welcoming your attendees calls for the unity that they are about to experience at your event.
If my boyfriend ever decides he wants to marry me in the future, and one of my friends knows, please direct his attention to this ring lol. PERFECTION! 2 CT ROUND CUT D/SI1 DIAMOND SOLITAIRE ENGAGEMENT RING 14K WHITE GOLD