My post below is in response to the above-named (see link also).
I thought this article demonstrated tremendous insight. I know nothing of your novel-writing but I too have been studying the (new) publishing world for about five years. I realised a while ago that my query letter was rubbish;
A new shoe-shop has opened in Villingili but the owner is taking no chances and has diversified. You might enter looking for footwear but you are just as likely to emerge with the latest in tinned tuna.