How does blog subscription differ from New Release list?
The new release list is the most important thing you can subscribe to. While I also mention new releases through the blog, the newsletter is the only list I control and have true access to. That means... if I change blogging platforms but you were subscribed only to my blog, you won't hear from me anymore.
You can always unsub from the new release list (see stickied post at the left to sign up) at any time, but it's the only way you are ENSURED of never missing anything.
But the New Release list is just for new releases. Occasionally I do sales or share sneak peeks of a book, and that happens here on the blog.