Perhaps you eagerly check each day your Amazon KDP reports page at https://kdp.amazon.com/reports
Both of the above will tell you how much money you've made but they won't tell you much about the number of each book you've sold. They won't tell you anything about your book sales at Apple, Barnes & Noble, Kobo or elsewhere.
So where do you go to get book sales information?
If you want Amazon information for the last six weeks+ try the link highlighted on https://kdp.amazon.com/reports
According to Amazon the Prior six weeks' Royalties is changing soon to a sales dashboard covering the last 90 days. Amazon say you'll be able to:
Under Units Ordered on the dashboard, you'll see a graph showing Paid Units, Kindle Edition Normalized Pages (KENP) Read (through Kindle Unlimited and the Kindle Owners' Lending Library for KDP Select-enrolled titles) and Free Units. You can filter the graph by Title, Marketplace, and Timeframe. Below the graph, you'll see a Royalties Earned table. This allows you to see your royalties for all marketplaces in the time period you select. The royalty amounts shown are updated only after orders have been finalized, which can be hours or days after the order has been placed. To see a detailed "Sales & Royalty Report," click "Generate Report." This report includes units sold, refunds, and royalties (excluding KOLL royalties) earned during your selected timeframe.
If you want results for a particular month then use the links at the right to get reports for individual months. These reports go way back - in my case to 2010. They'll tell you:
- What titles have sold on what days
- What your royalty rate is
- What the delivery charge was
- How much you earned for that book each day.
It's worthwhile keeping a record of daily sales and comparing that with promotions run on a particular day. That allows you to see if a promotion was cost effective.
Amazon are not the only book retailer though
If you want results from others, similar information is available. I use Smashwords to distribute to iBooks, B&N, Kobo and others. I can get details of my sales reports by using the links at the left of my 'Dashboard' there.
The daily sales link gives you a good overview of what has sold at each retailer but if you want a spreadsheet style display with details of individual books then use the 'Per-Payment Sales Report Generator' link to get a csv file.
What about other sources of information?
Try Novel Rank It will track sales of all books you register with it and provide informative charts. Unfortunately it only tracks paid sales. Free books don't count.
Kindle Nation Daily also have a page which tracks ebooks at http://tracker.kindlenationdaily.com/
This site tracks on an hourly basis as well as over 30 days and previous months so it's graphs are very useful to check the progress of promotions. Again you'll need to register the books you want to track - and it will track the rank of free books. If you are a reader (most successful authors are) then it will also send you an email alert if a particular ebook is offered free or on sale.