SuppleMENTAL results were discussed a great deal last year by SEO blogs and forums after many webmasters, myself included, noticed a large number of pages appearing in the Google search engine results pages. I remember getting a streak of fear in my gut when doing the “site” operator and seeing page after page of my sites’ results appear with the word “supplemental” beside them. Here is an example of a current “supped” Clickfire.com result:
It is widely understood that duplicate content one of the main triggers that sends a page into the supplemental results. The above example from page 2 of a directory category certainly seems to bear that out because most of the content on the page appears on other more important pages of Clickfire.com. It’s no surprise that a page like the above is supplemental, once I understand why.
I can get some degree of comfort from Google’s own definition of supplemental results (http://www.google.com/support/webmasters/bin/answer.py?answer=34473):
A supplemental result is just like a regular web result, except that it’s pulled from our supplemental index. We’re able to place fewer restraints on sites that we crawl for this supplemental index than we do on sites that are crawled for our main index. For example, the number of parameters in a URL might exclude a site from being crawled for inclusion in our main index; however, it could still be crawled and added to our supplemental index.
To further assuage fears, Matt Cutts recently indicated that Google’s supplemental search results should not be a cause of trepidation:
As a reminder, supplemental results aren’t something to be afraid of; I’ve got pages from my site in the supplemental results, for example.
Having urls in the supplemental results doesn’t mean that you have some sort of penalty at all; the main determinant of whether a url is in our main web index or in the supplemental index is PageRank.
It’s perfectly normal for a website to have pages in our main web index and our supplemental index.
The main point to be made here is that there is no reason to be afraid of something you understand and have control over. Results are results. It’s time to stop worrying and get busy uniquetizing those potentially suppy pages. If it’s any consolation, Google.com itself has plenty of pages listed as supplemental results.