In order to designate review content on a web site, the specific microformat hReview is used. It can assist in getting your review sites indexed and found by search engines like Bing, and make your site more friendly to other web applications. Microformats is a system which uses existing XHTML and HTML tags to pass information in a systematic way by describing what the content is for search engines and other web users. hCalendar - for events, hCard - for contact information, and hProduct - for products are examples of other specific microformats. When using microformats, your website isn't rendered any differently by the web browser. Microformats simply make the source code 'smarter' in a sense, and allow easier communication with web applications, to help them understand better what the underlying content is about.
The hReview microformat is broken into several different properties including the date/time the review was written, a summary of the review, the author, the item being reviewed, a rating, a permalink to the review, and others. For more information and specific formatting questions regarding hReview properties check out the following site: http://microformats.org/wiki/hreview-profile.
To learn how to create a review site to easily and automatically integrate the hReview microformat, check out this article: Creating A Review Site
Properly formatting and using the hReview microformat in your web content will allow you to take advantage of several web features including Google's Rich Snippets feature. Google defines this feature as 'giving users convenient summary information about their search results at a glance'. If you search 'piccolos italian restaurant' on Google the number one result includes a rich snippet summary of the reviews available on the City-Search site. With this rich snippet, the Google searcher can now see at a glance, a quick summary of the reviews for the particular product or service they were searching for. Google only pulls this data from your site if you are using the hReview in your source code.
To see the different types of review sites marketers use, with examples, read this post: Types Of Review Sites
With the data that hReview provides to the web surfer, you can be certain you will see more of a click through rate to your site when this data is used. It's nice to know some specific details before going any further and microformats allows you to easily give that extra info.
