Why do you care if it is done to your satisfaction when the prize is awarded based on other's satisfaction with it?
Why do I care... what I care? Seriously?
But I do agree with your expected utility calculations. The problem is, I can't motivate myself to write under conditions of uncertainty like that. I understand that shouldn't matter, especially since I consider such a project worthwhile even in the absence of $155, but it does.
Getting it done to other's satisfaction and getting it done to your own are not mutually exclusive. You can work quickly to win the prize and then go back and expand.
EDIT: I am canceling this contest because I feel that the structure of the incentives were poorly thought out (see gwern's comments). I will be posting a new better structured contest in the near future (now posted). If you feel this is unfair or otherwise feel slighted, please contact me at my username at gmail.com.
I'm interested in making projects happen on Less Wrong. In order to find out what works and to inspire others to try things too, I'm sponsoring the following small project:
I hereby offer a prize to the first person to submit a good summary of the evidence on Spaced Repetition to the main page. The winner will get the prize, currently: $265 + 40 to charity (see comments)
The summary should address at least the following questions: