To me, contests offer several things. First of all, they have a due date. I need this or I will procrastinate forever. Secondly, contests like this one (along with the Daily Flash Fiction Challenge) give me a reason/mandate to write daily. Third, short stories allow me to stretch my imagination and try new things (yesterday's poem) with very little risk timewise. Finally, I like the comradeship. The combination of competition and encouragement only make writing more fun.