P.S. the profits will be donated to a charity organization
Definitely put a note up, though. My first thought when seeing this was a vivid image of someone laughing all the way to the bank.
As far as I can tell this is a never-ending contest, so are you donating the proceeds to charity on a rolling basis as soon as you receive them?
And are you donating 100% to charity, or using a portion to pay for the website/server/bandwidth/development costs?