I enter about 100 of these types of open challenges a year and yeah, they often have abysmally low entry rates (one of the reasons I enter them), especially the winner take all competitions.<p>The people are very averse to doing work for no promised reward, so they do something else.<p>One of the main sites I enter contests on has a tiered system where the top 10% win a lot of money, the next 15% win basically a lunch, and the next 25% win a buck or two. It has really helped to boost participation.