1. You set the payment amount, but the default is exponential. (Edit: didn't read your comment thoroughly enough the first time to know you were referring to the OP, not the general policy.)
2. Payments are done via credit card, although Paypal support seems to be in the works.
3. It does not appear to be a non-profit. It looks like a business where Beeminder's living is made off of people paying when they fail their goals.
But maybe the best way to refute that is that we've been around 5.5 years and our long-term churn (not counting short-term churn of dabblers which is embarrassingly high cuz Beeminder is super nerdy and intimidating-looking!) is only 2%/month.
PS: Huge thanks to enoch_r for the beautiful testimonial!
I realize your feedback is about the impression it gives, totally separate from how greedy we actually are, but we're still tiny ($22k/mo revenue with 3.5 FTEs). And like enoch_r and mgiannopoulos have averred, paying the penalties to Beeminder generally feels super fair. So that's why we've limited the charity option to the ultra-VIP plan. (We're super open to more feedback about this though. We tend to get a highly biased sample of opinion from our users, i.e., the people who weren't immediately put off by our apparent greed. :))