Are you an affiliate marketer who uses the standard sales page that comes with the product your are selling? If you do, then you are probably not getting the search engine ranking you wanted.

Here's a fact. Google is implementing a duplicate content filter. One of the purpose they did that is because thousands and thousands of affiliate marketers are using the same sales page promoting the same product. Exact duplicates of these pages do not give value to the users of search engines.

The best way to overcome this is to tweak the sales page. Cut some parts, add some more content, paraphrase some paragraphs and rearrange the code. If it is a sales page uses tables to organize its layout, then probably you would like to convert it to CSS.

The more changes you have, the better chances that google wouldn't penalize your site for duplicate content.