Dollar Tree also recently added customer ratings and reviews to the site.

Currently, they have a customer rating of over 9.9 out of 10.

For consumers who are unfamiliar with a particular merchant, the site will display customer ratings.

The Good Reads website, as of September 2012, had 864 reader reviews and 6,320 customer ratings.

The average customer rating for the DVD from Amazon.com was four out of five stars.

Production values and the quality of instruction vary, so the customer ratings on a site like Amazon.com can be useful.

Both sites let customers post reviews of books; both display an average of the customer ratings in the form of one to five stars.

The Good Reads website, as of May 2012, had 598 reader reviews and 5,689 customer ratings.

You can also put customer ratings for products along with the item and even on the informational pages.

Friedman's book has been well received, with an average customer rating of 4.5 out of 5 stars on Amazon.com.