Win a Meeting With Your Hero and Help His Favorite Charity Even if Your Not Rich
From time to time, there is an auction for a meeting or talk with a pubic figure. The problem with this auction model is, that only people with money can contribute and only they can win the auction.
Instead of one person donating a large sum, have people donate smaller amounts (or larger ones if they want), and instead of an auction, have a raffle and a winner. Each person donating has the same chance, and you get all of the donations for the charity.