I have recently converted a few article "groups" into books. I basically went through certain taxonomy lists and used the "outline" tab for each one to add it to a top-level book page. The result that I found was that I got a much higher percentage of click-throughs with the book navigation than from a taxonomy listing.
Taxonomy Listings are Boring?
The original reason for converting from a listing to a book was because a client of mine was unhappy with the "text heavy" appearance of the listing - she wanted the feel of a portfolio. I had a hunch that the book module might be the answer when I noted that another area of the same website (Wedding Packages), which was a book, was doing well. Meaning that over half of the visitors were navigating from beginning to end.
Book Module to the Rescue!
So I converted the Wedding Gallery to a book. See the before and after here:
Wedding Gallery Taxonomy Listing
Wedding Gallery Book Navigation
Everyone Seems to Love Drupal Books...
The client and her staff reported that they thought it was now "fun" to click through the pages. Visitors seemed to like it as well and the traffic through the Galley increased. It was so successful that I grouped a several of my articles book-style.
Update: We are no longer managing this website so links have been removed.