Not that the information on those extra pages is necessarily useless, but it's something that can be worked into pieces of a cover letter or discussed at an interview. (stafkings.wordpress.com)
One does get wary of the various pieces of cover letter writing advice that one gets on the web. (coverlettersandresume.com)
To top it off, sometimes your own piece of cover does the exact opposite and you still get shot even when you are clearly fully in cover. (glitchcat.com)