I've always wondered if entering writing contests helps your writing career or not. Every writer's reference book I've ever bought, and believe me that's a lot of them, advises fledgling writers to enter them. I suppose they might be a good tool for those who win the grand prize and get a huge cash payment and a dream writing contract. What about for the rest of us who enter and place but don't win?
I have no confirmation they help one way or another, but I include them in my author's biography when I query an agent. To date, my claim to fame is a tenth place finish in the genre fiction category of the 2005 Writer's Digest annual fiction writing contest. I like to put a little more of a positive spin on it. When I query agents I say I was a top ten finisher. I do have a win in the romance category of the 2009 Reader View's Literary Awards that I'm particularly proud of and always include. Finally, I've made the quarter and semi finals of the Amazon Breakthrough Novel Awards.
Does this help make me more attractive to perspective agents? I don't know, but at least it gives me something to include on my resume as an unpublished, waiting to be discovered new author.
Will they help you? I don't know, but I say go for it. Just try not to get too emotionally invested in it. I hear these contests are as flooded with entries as agents are with queries.