There have been many inquires as to what supplemental listings are in Google
and why so many sites are effected. I put together this simple Q and A that
will help you find and correct problems your site may encounter with the
supplemental index.


What are supplemental results?

Supplemental results are Googles way of preventing questionable pages from
being found in the main index. Supplemental results are usually shown
after the main results. Supplemental results are crawled less and not
trusted by Google, which is why the are supplemental.


How do you know if any of your pages are in the supplemental?

Go to Google and use site:www.yoururl.Com. Look at all the urls of your
site. Supplemental results will indicate they are such next to the URL.


Can pages in the supplemental index rank on Google?

Yes, they can. But only if there aren't any other results available for the
phrase being searched.


What can cause a page to be added to the supplemental index and not the
main?

Supplemental status, the majority of the time, is something new sites
encounter. However, if you have given Google a reason not to trust your site or content, you can also be placed in the supplemental results. Any of the following can also cause you to hit the supplemental results:

Not enough content on the page
Duplicate content
Too many query strings in the URL
Orphaned pages... Pages not linked to any other inside your site
Titles and descriptions the same on every page
All links to your site are reciprocals and possibly to bad neighbors
A page that no longer exists may have an old cached version of itself in the
supplemental listings

Any of these alone or a combination of these can cause your pages to be in
the supplemental index. Keeping these factors in mind when creating pages
will help you avoid it. A good example of a site that is a prone target for
getting into the supplemental is an e-commerce sites. These site's generally
have have long query strings and are filled with duplicated product listings
on different pages.

Facts:

If you are in the supplemental, you are being crawled.
You are not in the main index.
You need to take action to get out of the supplemental index.

Once you have made the corrections, be patient. Google indexes supplemental
pages less. Working in backlinks to these pages may help. If you have any
other problems getting out of the supplemental index, try asking on forums
or obtaining info from SEO podcasts.