Does every page on your website add value to the overall concept you are advertising/promoting/selling on your website? If it does not add value then why have it? Having such pages on your website just confuses people making it harder for them to find the information they are looking for. Additionally search engines find it very difficult to find rank pages which don’t have a clear purpose so they don’t end up being very high in the rankings. Clear informative pages with real value rank well.