tl:dr; Can I receive money for doing well in a goal?
In operant conditioning Beeminder is using active avoidance as a negative reinforcement of the behaviour. “I’ll lose money if I don’t do it”. There is one other option which would also provide the same outcome namely positive reinforcement. “I’ll gain money if I do it”.
Combined with a variable ratio reward schedule, people would be more likely to stick to their goals.