Have you ever searched your website in Google by using the “site:” method?  If you have you’re likely to have come across a page classed as a supplemental result, often near the end of the search results.

Supplemental results are part of Google’s auxiliary index pages, as apposed to results from Google’s main index.  Supplemental results which appear on the supplemental listing, have “fewer restrictions” than those that appear on the main results page.

Often only sections of a website are deemed supplemental, however there are times when a whole website is categorised as a supplemental result.  Your entire website being categorised as supplemental by Google is one of the worst case scenarios a webmaster can face.  This is because supplemental results are only included when the main index fails, or there are very few results in the main index.

Google’s Adam Lasnik has stated that when your site has pages in a supplemental index, it does not indicate that your site has been penalized.   Even though this is probably correct, the effects are the same as being penalised.

Unfortunately there is no sure fire method of making sure your website won’t ever be shoved into the supplemental database as there are several factors which can lead to it.  The actions you can take on your website are well known Search Engine Optimisation techniques that will give your website the best possible chance of avoiding it.

Tags
A good Search Engine Optimisation starter is always with your website’s tags.  If possibly, try not to use the same title tag for more than one page.  Page titles should always be relevant to the content and should not be very long.
 Always make sure your page titles do not look like spam as Google will almost always send pages that it thinks spam-ridden to the supplemental index.  Ways to avoid having “spammy” titles is to avoid too many and identical keywords.
These methods should be applied to the websites description and keywords.  The keywords and descriptions should not be too long or repetitive as they will be considered to be spam. 

Content
Content is a key area of Search Engine Optimisation for a variety of reasons.  Webpages should be bursting with quality content to feed Googles needs.   It’s worth noting that image tags, prices and small descriptive text is usually not considered to be high quality content, as Google generally considers these as commercial page content.
Duplicated content text throughout the website is likely to result in that section of the website being included as a supplemental result. For example a blog website which uses categories is likely to find its individual stories as supplemental results, but the main pages and category pages will generally not be.
If your website is lacking in content, then the first thing you need to do is to write some.  A few lines of text is not enough, no page should have less than 50 words.  If you are writing an article or news post, 500 to 1000 words is a good number to hit.
 The content on your pages should always be relevant to your subject for search engine optimisation purposes.  For website marketing purposes make sure that visitors will want to and enjoy reading it where webmasters will want to publish it (with your permission of course).
If you have “acquired” content from other websites, re-write the content to ensure your content is considered to be unique or at least not spam.  Always sourcing information from different websites and reconstructing the content is a good way.

Structure
A website’s structure is also very important for SEO success.  Pages that have few backlinks are likely to be seen as supplemental results along with pages that are buried deep within a website’s structure.  These pages are more than likely going to be considered far less important compared to more accessible webpages.
It is considered that three clicks is the maximum amount to get from A to C, however you should be aiming for no more than two clicks to navigate throughout a website.
If your website is guilty of poor link structure, it is important to change it sooner rather than later.  A good place to begin with is to send all your back links to more than one page.

Links
It’s a good idea to check how many backlinks your website has in the Google database, this can be done by doing a “link:” search to your website.  If you haven’t got many links it’s recommended that you do everything possible to get more quality backlinks: Google’s Adam Lasnik states “This is a key way that our algorithms will view your pages as more valuable to retain in our main index.”

URL
Long url’s or url’s with lots of dashes are also generally thought of as spam by Google and therefore is not good Search Engine Optimisation practise. This is the reason why many pages hosted by free sites end up in the supplemental index. Always keep your webpage URLs as small as possible and for better Search Engine Optimisation always use – instead of _ to separate words.

If you have spent time reconstructing your now supplemental website with the above pointers, its more than likely all (or at least the majority) will now be back in Google’s main index.
However there are occasions where there will be a few web pages will remain in the supplemental results page.

If this is the case, it would be a good idea to make some new, more prominent links to these pages from your home page.   If this fails, you could always try re-publishing the content on a new URL, with a juicy link to it from your homepage.

It’s important to realise that if your website or web pages has already been demoted to the supplemental index, there is no guarantee that you can earn a place back onto the main index.

With this in mind, always follow the steps to ensure that your beloved website doesn’t find a new home in the supplemental index and enjoy the rewards of a fully Search Engine Optimised and highly placed website!