Hack 28 Link Directly to Reviews of a Product

With a little URL hacking, you can link directly to any product's reviews from another web site.

Reviews are one of the most interesting pieces of community information available on Amazon. A positive or negative review rating can have a big impact on an item's sales. Naturally some people are very interested in this information: publishers, authors, other merchants, or fans of a particular book, DVD, or CD.

Each item's product detail page shows a handful of reviews, but if there are dozens—or sometimes hundreds—of reviews, most are tucked away on that item's Customer Reviews page. Once you know the URL format for this page, you can link to it directly with any item's ASIN. And once you have the URL, you can link directly to the page from another web site.

Keep in mind that Amazon URLs change from time to time, but as of this writing you can simply designate the ASIN in this URL:

http://amazon.com/o/tg/detail/-/insert ASIN/?vi=customer-reviews

There are 10 reviews per page, so if there are more than 10 reviews for the product, you can go directly to other pages by adding page numbers to the URL:

http://amazon.com/o/tg/detail/-/insert ASIN/insert page/?vi=customer-reviews

So, the following URL would take you to the second page of reviews for Google Hacks:

http://amazon.com/o/tg/detail/-/0596004478/2/?vi=customer-reviews

By default the reviews are ranked by date with the newest first. The simplest way to change the order in which they're returned is to choose a sort method at the site, as shown in Figure 3-1.

Figure 3-1. Sorting customer reviews

You can also change the sort value in the URL, so you can link directly to a sorted list of reviews. By appending &show= to the URL with various values, you can perform the same actions that are available at the site.

For example, if you want to link directly to reviews of Google Hacks with the most helpful reviews (as voted by Amazon users) listed first, the following URL would work:

http://amazon.com/o/tg/detail/-/0596004478/?vi=customer-reviews&show=-rating

Table 3-1 shows the available sorting methods and associated values for the show variable.

Table 3-1. Customer Reviews sort methods

Show variable value	Sort order
-submittime	Newest first
+submittime	Oldest first
-rating	Highest rating
+rating	Lowest rating
-votes	Most helpful
+votes	Least helpful

To view only certain ratings, set show to the number of stars:

http://amazon.com/o/tg/detail/-/0596004478/?vi=customer-reviews&show=5

This URL will show only 5-star reviews for Google Hacks.