A number of pages on a very niche site are not performing well. They are fully optimised along the same tack as pages ranking highly. The only major difference seems to be the amount of content on the poor performing pages. There is significantly more content on those pages that are under performing. All pages have a similar amount of keywords so could it be that the keywords are being 'damaged' by having a lower % presence on those pages? Just a thought (Grasping at straws)
possibly. It could be making your pages more generalized. Paging may help. Each break each article down into pages of 500 words each.
In addition to word count, any number of other factors could be at play. Without actually reviewing the page(s) in question, speculation could also include: * competition for targeted key phrases * the SEO incorporated * inbound text link(s) to file(s) (on-site & off-site) * age of file(s) + age of site * age of, and the number of inbounds to file(s) * association with similar industry sites * HTML configuration & access to the file(s) * download speeds * code validation * etc., etc. Generally, pages perform best with between 250 - 1,500 words per document. However, your text content only provides the foundation and the potential for further positioning based on additional work.
I do agree with you too. If you are tagetting just one keyword then contents weakens keywords for sure.....but this happens only in-case your content is full of with other good keywords but not related to your targetted keyword.
More traffic possibly. But if that traffic is visiting my site because I have the word Egg in the content and I am selling Hammers then pretty useless traffic!!