Big Brother Is Watching!

From an Amazon.com webpage, "Most popular Kindle hightlights:"

(click to enlarge)

And from that webpage's What's this? link:

The Amazon Kindle, Kindle for iPhone and Kindle for iPad each provide a very simple mechanism for adding highlights. Every month, Kindle customers highlight millions of book passages that are meaningful to them.

We combine the highlights of all Kindle customers and identify the passages with the most highlights. The resulting Popular Highlights help readers to focus on passages that are meaningful to the greatest number of people. We show only passages where the highlights of at least three distinct customers overlap, and we do not show which customers made those highlights.

The Most Highlighted of All Time passages have been highlighted by the most distinct customers. The Most Highlighted of All Time books are ranked based on a combination of number of highlighting customers and number of highlights. For Heavily Highlighted Recently passages and books the ranking is done in a similar fashion, but with a much greater emphasis on highlighting that was done recently over highlighting that was done a longer time ago.

Does the information gathered help Amazon sell more books? If so, how?