How can authors of books and book chapters track the impact of their published works? Several ways include:

• How many libraries hold the book in their collections? Check WorldCat to find how many libraries have a record for the book in their collections.
• Is the book noted on any Best Seller lists?
• Are there any book reviews?  To find book reviews, check bibliographic databases that index book reviews, Google Books, Amazon, Barnes and Noble, publisher websites, to name a few. Some reviews are available in video format.
• Are there any discussions about the book in the Amazon Customer Discussion forum?
• Is the book available in an e-reader format as well as print?
• Has the book been publicly recommended on Google+?
• Has the book been tweeted on Twitter?
• Is the book noted on a publisher’s best-seller list?
• What are the sales figures for the book?
• Has the book been included in bibliographies?
• Has the book or book chapter been cited in subsequent publications? Some bibliographic databases provide citation data to book or book chapters from scholarly literature. One example of a database is the Thomson Reuters Book Citation Index.
• Has the author been invited to present on the topic related to the book or book chapter?
• Has the author been invited to book signings?
• Are there subsequent editions to the book?
• Are there any translations of the book?
• Has your book been awarded any prizes such as the PROSE Award or noted by an organization as having made a significant contribution to a field?

Any others?