> We do not make anything from the contracts because it seemed wrong to profit from our users failing. We want our incentives to be aligned correctly!

I assumed that the monthly fee was on top of a percentage fee on lost bets, which other platforms charge. You should make this more prominent on the site — aligned incentives are great!

> We do not make anything from the contracts because it seemed wrong to profit from our users failing.

This is how naive good-meaning founders start evil parasitic businesses that don't realize their true potential until the buyout...

Since you're allowing people to donate to charities or "anti-charities," you should just allow the user to specify a % fee that goes to you. If I set up a $1,000 contract to go to some Nazi org if I fail, I'd much rather $1 go to the Nazi org and $999 to you.