Our Webmaster Guidelines advise you to create websites with original content that adds value for users. This is particularly important for sites that participate in affiliate programs. Typically, affiliate websites feature product descriptions that appear on sites across that affiliate network. As a result, sites featuring mostly content from affiliate networks can suffer in Google’s search rankings, because they do not have enough added value content that differentiates them from other sites on the web. Added value means additional meaningful content or features, such as additional information about price, purchasing location, or product category.

Google believes that pure, or “thin,” affiliate websites do not provide additional value for web users, especially (but not only) if they are part of a program that distributes its content across a network of affiliates. These sites often appear to be cookie-cutter sites or templates the same or similar content replicated within the same site, or across multiple domains or languages. Because a search results page could return several of these sites, all with the same content, thin affiliates create a frustrating user experience.

Exampes of thin affiliates:

• Pages with product affiliate links on which the product descriptions and reviews are copied directly from the original merchant without any original content or added value.
• Pages of product affiliation where the majority of the site is made for affiliation and contains a limited amount of original content or added value for users.

Not every site that participates in an affiliate program is a thin affiliate. Good affiliates add value, for example by offering original product reviews, ratings, navigation of products or categories, and product comparisons. If you participate in an affiliate program, there are a number of steps you can take to help your site stand out and differentiate your site:

• Affiliate program content should form only a minor part of the content of your site if the content adds no additional features.
• Ask yourself why a user would want to visit your site first rather than visiting the original merchant directly. Make sure your site adds substantial value beyond simply republishing content available from the original merchant.
• When selecting an affiliate program, choose a product category appropriate for your intended audience. The more targeted the affiliate program is to your site’s content, the more value it will add and the more likely you will be to rank better in Google search results and make money from the program. For example, a well-maintained site about hiking in the Alps could consider an affiliate partnership with a supplier who sells hiking books rather than office supplies.
• Use your website to build community among your users. This will help build a loyal readership, and can also create a source of information on the subject you are writing about. For example, discussion forums, user reviews, and blogs all offer unique content and provide value to users.
• Keep your content updated and relevant. Fresh, on-topic information increases the likelihood that your content will be crawled by Googlebot and clicked on by users.

Pure affiliate sites consisting of content that appears in many other places on the web are highly unlikely to perform well in Google search results and may be negatively perceived by search engines. Unique, relevant content provides value to users and distinguishes your site from other affiliates, making it more likely to rank well in Google search results.