This is a great resource for speculative writers. I just came across it myself. They have forums to find out about missing markets, new markets, etc. All the online stuff appears to be free, but if you want to subscribe to their e-mail newsletter, it’s 20 bucks a month.
I have only just started checking out the online content, but if their newsletter has anywhere near the amount of info the online site has, it is well worth 20 dollars.
Check it out.