I read a blog post that in my opinion offered poor link building advice. The article was about driving links to the home page. I believe it’s important to be aware of how many links are going to the home page.
Nobody can know for certain if there’s an optimal home page to deep link ratio. Google doesn’t publicize that kind of information. So the ideas contained in this article must be circumspect in its conclusions.
Up to 50% links to Home Page a Bad Thing?
The blogger suggested that an ideal of 30% to 50% home page links was realistic.
Neither the 30% nor 50% home page link targets are justified by any observations or study. Those percentages reflect his goals as a reaction to the difficulty of encouraging natural links to product pages.
Balancing the home page to deep link ratio might be useful.The SEO blogger also stated their (unsubstantiated) opinion that it is common for sites to link to the home pages of other sites.
An excess of home page links has been noted to be a statistical quality of sites that are creating unnatural links. For example, a study from 2006 entitled, “Link-Based Characterization and Detection of Web Spam” the author states that a statistical study of inbound linking patterns discovered that sites with in-links predominantly to the home page tended to be spam.
According to that research, non-spam sites tend to have more links to inner pages than to the home page. See section 3 of the study (PDF).
Several years ago I started using SEO tool to sample a variety of search queries across a range of niches to find their home page to deep link ratios and have continued to monitor linking patterns. There are many tools that offer the home page to deep link metric.
What I found was that the inbound link ratio of sites that ranked in the top ten of Google’s SERPs tended to feature more deep links than home page links. But that wasn’t true across the board.
Here are some exceptions:
1. For queries with a geographic component, top ranked sites tended to acquire a higher ratio of links to the home page. This makes sense because the home page will be the answer to local based queries.
2. Corporate pages
Some corporate pages are dry and don’t feature link-worthy content on the inner pages.
3. Competitive Topics
It could be that a lack of sites that would link to inner pages in a natural way are rare. For example, what blogger or web publisher would enthusiastically link to a PayDay loan or gambling website?
Deep Link to Home Page Ratios
I found that top ranked online retail sites tended to have a higher ratio of deep links to home page links.
Some sites like gasoline station brands, tended to have more links to the home page. That may reflect a natural linking pattern.
Will Too Many Home Page Links Affect Your Rankings?
I don’t think Google is using deep link to home page ratios to determine if a site is spammy. Many Fortune 500 sites have more home page links than inner page links. Clearly, the home page to deep link signal by itself cannot predict the spamminess of a site.
I believe that publicizing inner pages so that they earn links is better than driving links to the home page and hoping that enough PageRank will trickle down to the important product pages. A link is a vote. It tells Google that a page is important.
So it makes sense that a natural and relevant link to a product page is better than a link to the home page. That’s why I believe, based on my experience, that encouraging links to the pages you want to rank is a better strategy than encouraging links to the home page.