Keyword Cannibalization

[Alexsmenaru]

How harmful can be a keyword cannibalization? And what is the solution to this problem?

[EGOL]

Keyword cannibalization can occur if you have lots of pages on a single site that target the same keywords.  That situation creates multiple pages on your site that compete with one another.

Google currently will display three, four or five pages in the SERPs for a single keyword from a single site - so if you can create three strong pages for a single keyword you might be able to get #1, #2 and #3 in the SERPs.

example  (note how shop.nationalgeographic.com has three listings - ranking #2 through #4 as I view them here in the USA)  (amazon has two pages here as I view that SERP)

If you have 10 pages targeting the same keyword then that is overkill because google will not display that many in any SERP.  So some of those pages and the linkjuice that supports them is wasted - that is the harm that you asked about.

You would probably be better off combining information on those ten pages  to make two or three more substantive pages or even one SuperKickAss page for the topic (which will probably rank better and pull a ton more longtail traffic)

[SteveOllington]

You just need to ensure that there are set pages with relevant keywords for them, and don't cross the keywords with the other pages.

There's two SEOmoz articles on it by Rand from ages ago here:

http://www.seomoz.org/blog/keyword-selfcannibalization

http://www.seomoz.org/blog/how-to-solve-keyword-cannibalization