If your book is traditionally published, you may not have any idea how many units you've sold until you receive a royalty statement from your publisher. With some publishers, this may only be once or twice a year!

One of the most useful tools that I've found to monitor sales of my books are the Amazon sales estimator tools. There are plenty of links to different versions of these tools, just search for that term and you'll find one. These work by estimating your daily and monthly sales by using your book's ranking on Amazon. To find your book's ranking, navigate to the listing and scroll down to Product Details.

Since Kindle book sales are not reported by BookScan, these free estimator tools can give you some valuable information on how many Kindle and print books you're selling at any given time.

Troy Hollan - author of Clucked - A Quirky Nautical Tale of Adventure, Misadventure and Justice Served