Rankforest can now track actual sales at Amazon.com. The sales date and quantity are provided in a list format and can be used in conjunction with the charts to see how much a certain sales volume affects sales rank.

The primary limitation is that the sales must be mediated by the Rankforest website. For example, there are see this on Amazon.com links on each item’s detail page. These links lead to Amazon.com, and, if the item is purchased, the sales are tracked. Each item also has a special tracking URL that you can copy and paste into your own site. Using the URL is effectively just like linking to the item on Amazon.com, with the added bonus of having purchases tracked.

This feature is most beneficial to items that sell in relatively small quantities. A single author or small publisher that makes the majority of their sales through their own website links to Amazon.com could more accurately gauge the relationship between sales volume and sales rank.

The sales volume data will be updated at the end of each month. There are already several months of data available for any books that have sold through Rankforest in the past. The data for February will be posted in another week, so if you’re curious to see how things work you still have time to make purchases this month.

Any sales generated through these links benefit Rankforest.com. You can read a little more about this feature on the main page.

Rankforest will be undergoing some minor server updates this weekend. Downtime should be limited to a couple of minutes. I’m also working on a new feature that I hope you’ll find exciting. Rankforest will soon start showing Amazon.com sales data for books bought through Rankforest.com. I’ll provide more details when the feature launches.

Some of you may have noticed that even if you had a paying account you couldn’t see beyond 30 days when selecting a date range from the drop-down on the book detail page. This was definitely a problem and it should be fixed now.