What's the solution? Make a flyer that is easy to read. The Optimist Club of Issaquah, Washington has great success with the Optimist Essay Contest. I think it has a lot to do with their simple, straightforward marketing approach that begins with this flyer.
The Issaquah Optimist Club has also secured a good relationship with their school district and the scholarship contests are published on the school district websites.
It does take a little work to promote activities in your community, but the increased participation will make it all worth it.