Just ran across a cracking article in Chuck Sambuchino's blog for October 8, 2014. It's written by a guest author, the New Zealand YA fantasy writer David Hair. I think it's well worth a look, as it's a topic which concerns many people here on this forum. Here's a quote of the first two paragraphs of the article. I'm not sure if the link works, but it's worth a try. If not, just Google Chuck Sambuchino's link to his blog and go from there.