Cash, did someone say free cash - you'll be swamped lol.
Sounds like a lot of work from your part, but way to go... Kudos friend.
I've not seen one of your contests before, but from what I've noticed, having some way to spread the winners around and ensuring everyone has an equal chance of success. Too many contests seem to reward the already established i.e. the rich get richer scenario.
Good luck 👍