PublisherChamp is an amazing tool for authors. My favorite thing about it is how it lets you see your ad spend vs your book revenue, so you can make sure your series is profitable over time at a glance. The power table is amazing, and can do all sorts of comparisons, like comparing paperback sales by country and by series. This is an amazing tool and even after using it for years, I still feel like I am finding new ways of using it, partly because the developer is a busy bee who is always giving us authors more useful features! He's also very responsive to bug reports, feature requests, etc.