It might result in much higher income.
Offer your product with an exceptionally big and attractive bonus in an open auction (everyone sees all the bids.) The starting price is $1, and each increment is also $1. The auction ends when there is only one bidder left. That person gets the product with the special bonus. Everyone else gets it for the amount of their last bid but without the bonus.
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.