I assume it's organized to attract and bring it wealthy individuals, who I suspect are not the easiest to get time with. When you think about it, it's a small price to pay to get a large group of billionaires in the same room and what their prospective business/donations could be worth depending on what you're selling/promoting.

Just think the type of people you get in to the same room who normally wouldn't give you the time of day if you had obama agree to give a private talk.