about $300 or so, much of it front-loaded towards early on when I was still gaining some necessary meta-habits, like "check beeminder carefully every morning/night."
> How do you make payments (escrow, credit card, PayPal, etc)?
They're credit card only for now.
> It seems like this would be a great opportunity for a non-profit.
I have no problem rewarding Beeminder for a service I find many times more valuable than what I pay them. Paying Beeminder my pledges is voluntary and mutually beneficial--they get an incentive to keep the service running, I get an incentive to improve my behavior. I like giving to charity too, but I'm fine with my Beeminder contracts strictly rewarding Beeminder.