Another good thing to look at is domain authority and core page authority. If your site has had a few redesigns, moved URLs, or anything like that, it’s important to make sure that the domain authority has carried over. It’s also important to look at the page authorities of your core pages. If these are much lower than when they were before the organic traffic slide, there’s a good chance your redirects weren’t done properly, and the page authority isn’t being carried over through those new domains.
Hi Brankica, I'm a total Kindle addict too! As much as I love to hoard books, the Kindle makes it even easier to consume books in volume! One other suggestion: There's a nifty new service called http://paywithatweet.com that allows you to give away an electronic download in exchange for a Tweet or post on Facebook. I LOVE this and have been testing it out with my latest book. Very effective!