Back in September 2003, the launch of the Supplemental Index led to outcries from the webmaster community because pages included in it were deemed as secondary; thus, leading to the death of their sites’ SEO. This type of index may have been rolled out to allow bots to crawl through and index more pages without users suffering from reduced quality and performance of the search engine. With this November 2006 update, Google rolled out new guidelines that changed how the search engine handled websites that were affected by their filters.

What’s It For

The supplemental index is described as a secondary directory of pages that Google provides to end users in case the query fails to find relevant matches from the primary index. Search terms from this set have the tag “supplemental results” beside the URL in the SERPs.

For some websites, the restrictions implemented in the main index may be ignored for the supplemental index. This freedom allows bots to crawl through sites that may have low trust scores in the main one. However, most pages listed in the secondary directory are often not displayed as results in search queries.

What Were Its Effects

There was confusion on the exact cause of a page’s exclusion from the main index and its fall into the supplemental. It caused outcries of frustration from webmasters whose websites suffered from the loss in rankings. Nonetheless, Google was adamant that the supplemental index was not a horrible place for your site to be in.

Google clarified these three points regarding the supplemental index update

• Penalty – As mentioned above, the developers insisted that the presence of your pages in the supplemental index doesn’t equate to penalization. They confirmed that the migration of sites from the main index to the supplemental one doesn’t indicate a violation of the Webmaster Guidelines.
• Freshness – A “fresher” supplemental index was rolled out. Nonetheless, because it’s only secondary to the main directory, Google admitted that it wouldn’t be as comprehensive or frequently updated as the primary index.
• Cure – According to the search engine, more high-quality backlinks are the supposed cure for being in the supplemental index since the algorithm will view your pages as reliable sources of valuable information; thus, retaining your spot in the main index. However, some saw this as an admission that it’s a problem if your site is in the secondary directory because it needs treatment.

What It Means for You

Google had officially scrapped the supplemental results label in July 2007. This move was made to lessen the bias against pages listed in the supplemental index, which were seen as inferior or unimportant to the ones in the main directory.

Since the supplemental index update, the team has revamped the system that crawls and indexes supplemental results. When the label was relinquished, the system at the time conducted more in-depth and more continuous indexing. Now, instead of fixating on whether your pages are in the primary or supplemental index, you should focus on acquiring high-quality backlinks as Google recommended.

Here are the ways to build high-quality backlinks from scratch:

• Build Valuable Relationships In any business or industry, networking and being able to build relationships with others is crucial for success. The same goes for SEO; you must be able to connect with peers and influencers in your niche so that you get to introduce your brand to them. One way to leverage public relations is to be active on social media and share interesting posts.
• Produce Compelling Content Next, start your backlinking efforts right by producing compelling content that will attract your target audience. You need to have engaging posts in your blog that will entice and encourage potential partner sites to promote your link in their content. Popular types include infographics and original studies.
• Write Testimonials for Other Brands Another way to generate backlinks is to write testimonials for other brands. While this may seem counterintuitive, websites often include your link beside your name when crediting your review. It’s an easy method of getting backlinks and helping fellow entrepreneurs.
• Link Externally Link building is generally a give-and-take scenario. You shouldn’t be afraid to take the first step and cite authoritative websites as your sources. It not only helps boost your credibility, but it also provides an opportunity for you to show them how much you enjoyed their content. At this point, you can reach out to them and build a relationship with the site operator in hopes that they’ll give you a backlink in their future blog posts.