Andy, I'm all for open events. My point applied to all event types. Inviting a user applies to open events too, this increases the chances of them joining (open events have invites too). You know, getting friends and such to join. The option is to get a consensus on the invited people to see if they looked at the invite and to get an idea of who is going. So lets say I post a open event that allows anyone to join. I send a invite to everyone from the stacked team only. While I want anyone who is willing to be fun to join, I specifically want certain people or at least know what they are up to. This allows me to get an idea of who is not going to the event and plan accordingly. Random people saying they are not joining isn't very helpful.