A couple of years ago I found this great free website that would alert you when an author had a new release. I have not seen anything else like it on the web.
http://www.authoralerts.com/
From my understanding, it used data from Amazon. It would send me an email when a book came out with a hyperlink to the web page on Amazon. I had 20 or so authors in my list. Recently it stopped notifying me and I received an email notifying me the service will no longer be available. Does anyone know of anything like this? If not, some of you with the knowledge to replicate this might find an opportunity. I, for one, would be willing to pay a reasonable fee for this service.