As an art teacher I can see the value in the yearbook cover. It's not going to hang in the hall for a week and get torn down. It's not being shipped out of state and we never ever hear back about who (if anyone) ever won.
So, I am totally down with yearbook cover contests. And as the yearbook advisor, this works out just fine for me! But in case you are NOT the yearbook advisor, here's a lesson plan to get you through the one contest your principal will not allow you to skip.