With deadlines, people can become more engaged to do it soon. Without it, some pepople (including me) would think: hum... I'm doing this later... and later... and never :P (ok, I'm an exaggerated person :P ). But this kind of "preassure" helps to have works posted^^. Also, as a challenge, part of it consists on composing the miniature in a short time (one week). As komposers, we must be able to compose under pressure an with deadlines (believe me, I've been hired to compose two soundtracks for dance presentations, and that was a VERY BIG preassure.... I had to do much more than 10 bars in even less time =/ ).