I think the difference is that this website isn't a generic habit forming tool. There's a specific goal and the website will provide you information on how to achieve it.

According to the FAQ:

> Pay the $20 pledge and follow the Zen Master’s instructions that are emailed to you

That said, I'm not very comfortable with this website since the parameters for success and the content of the program are not clearly defined before you commit... and 20$ isn't a throwaway amount in my local currency (besides there's the inconvenience that even if the money is returned, I will loose the currency conversion cost).