Now what exactly is the supplemental index?
It is quite self explanatory actually. It is a supplemental index. A index supplement to the regular index, one where sites of lower value are placed. Pages that Google determines are of low value are stuck in this index. This index even has its own Supplemental robot according to Matt Cutts(official Google guy). However this robot doesn’t crawl normally like the regular Google robot crawls. It takes weeks, even months for the supp robot to come back and re-index your site. So changes to pages that are located in the supp index will likely not be recorded for a while.
On top of that supplemental sites are restricted from ranking for anything even slightly competitive. So being in this index is definitely not something you will want. However you get no say, or do you?
What causes a sites pages to go supplemental?
There are a variety of reasons why a page could go supplemental. Before I show you the factors that can cause a page to go supplemental I want you to google index download that in and of themselves they may not do it. Combined there is a high likelihood that the page may go supplemental.
Write quality articles/content related to your site. Put your hear and soul into it. If you wondering if Google can tell then yes I believe they can in a way. Good content attracts links which will keep you out of the supp index.Don’t upload partial sites. What I mean is don’t upload a few pages which might link to other pages not uploaded. Don’t put up pages with only a few words or so-called articles which contain 50 words.
By using the above listed factors use a reverse battle plan to fix any of these issues that may be on your site. Keep your title and description tags targeted and relative and whatever you do never stuff them. Even if this doesn’t cause a supp page it looks spammy and disvalues your title tag. Maintain a strong linking structure both in your site and backlinks. Don’t send all your backlinks to one of your pages, send them throughout all pages. Don’t let your pages get orphaned. For a relatively small site three links deep from the home page is far enough. Create a html sitemap which links to all your pages. Link to the sitemap from all pages.
The supplemental index can also be avoided using these same methods. Try to keep your work original, and build quality articles which will attract links. A good amount of links to a article will keep it in good standing.