Link building is by far one of the most important and often misunderstood elements of optimizing a site for search. Search & Social deals with clients on a daily basis who understand the need for links in general, but do not understand why they are needed, and definitely not how to evaluate their value or obtain them. Because of this I have decided to write a series of guides to different aspects of link building. My hope is that these guides can serve as training documents for link builders, and help clear up confusion about link metrics and acquisition techniques.
Learning how to evaluate a possible, or previously built link, is the foundation to quality link building. Without that skill you will not be able to make heads or tails of a quality link bait campaign and any webmaster outreach will be useless.
All links have some type of value, and a healthy link portfolio is comprised of low to high quality links. This is because a quality link portfolio is a natural link portfolio. However, understanding differences in quality can help unlock effective link acquisition goals and campaigns.
A great piece of secondary reading for this post is Wiep’s Link Value Factors. It gives expert opinions on many of these metrics.
Quick Tip: Make sure your highest quality links are passing a variation of your most valuable key terms.
When evaluating your link portfolio or thinking about how to acquire a link from a site it is imperative to ponder anchor text. Few metrics carry as much weight as the actual anchor text of a link, and the wrong anchor text can drastically change the value of a link.
For example, let’s say you were able to obtain a guest post on a highly valued blog in your market. You were able to get the owner to agree to one link placement and asked them to link to your site with the term “blue widget” in your bio. Instead the owner linked “visit the authors site” in your bio to your website. This link, while possibly having many of the characteristics of quality links we will discuss below, does not contain the anchor text for your most coveted keyword. It is not worthless, but it is not worth as much as it could be.
Keeping an active audit of your link portfolio and anchor text is a must. It allows you to notice any fluctuations in link gain/loss and respond accordingly.
Link Page Authority
Quick Tip: Use Yahoo’s Site Explorer to investigate the external links shooting to internal pages
Sadly this is one of the metrics I think many link builders look directly past.
New SEOs are often beat over the head with the concept of homepage PR being a metric of quality of any link on that site. Like a child in kindergarten, they run to their colleagues with the news, “I just got a link from a PR5 blog!”
Too bad the posts on the blog you got the link from usually move off of the homepage within an hour, and a majority of posts are not getting internal link equity. No internal links, and no visibility for linking, make for a pretty low quality link.
When evaluating the quality of a link always take into account page level link equity, or at least the pages ability to obtain links. For example, if you are doing a copious amount of blogger outreach you will not be looking for pages with high inbound links since they are new pages, but you will want to check earlier on the blogs to see if they are gaining links and internal equity.
This is an important part of the auditing process as well. Your higher quality links may become so after acquisition due to the page link equity.
Quick Tip: Use SEOmoz’s free version of LinkScape to get an indication of domain authority.
No worries PR fans, this metric is for you.
Well kind of. Toolbar PR is a reflection of actual historical PR documented roughly ever quarter. PageRank, as we all know is “a numerical weighting to each element of a hyperlinked set of documents.” The weighting is based on several factors and largely boils down to quality of inbound links.
When evaluating a link, regardless of the page it is found, it is paramount to investigate the authority of the domain. This is especially true because it works both ways. A link from or to a site with a corrupted authority, no matter how desirable the page may look, can be a ticket to serious issues. We have seen cases in client work where a single link to a questionable domain put a site into a penalty situation; we have also seen the effects of “negative seo” as a competitive tool.
Links on a page
Quick Tip: Don’t chase a link on a page with more than 50 other links
A page only has so much link equity to spread. The more internal and outbound links a page has the less the link equity can spread to any single link. Think of a web page like a Dixie cup full of water that is being refilled by a pitcher. If you poke one hole in the cup a small trickle of water will begin to spill as you maintain the water level with your pitcher. If you add a second hole the flow of water will increase. If you continue to add holes the more rapidly you will need to fill the cup in order to keep it full.
The issue also arises that often times pages that have massive amounts of links carry little to no value. Engines can easily devalue “links” or “resources” pages, and a page with nothing but links may veer from useless to dangerous dependent on who else is setting up shop on that page.
Age of Domain
Quick Tip: Domain age is more of a quality metric than a metric you should base acquisition on.
Domain age is really several concepts boiled into one:
1) Search engines tend to put more trust into websites that have been around a while
2) The older the site, the longer it has been building links, thus building links from other trusted sites
When looking at sites to feed into your link building campaign you should utilize a tool like SEO Toolbar to scope out the age of the domain. This will help you rate and prioritize your link acquisition campaign.
Relevant Authority of the Link Page
Quick Tip: Don’t waste your time killing yourself getting links from your competitors. However, use their relevance and link portfolio as a roadmap.
This is one of the trickier link metrics because in the end if you only gauged links as valuable by their relevant authority then you would only be trying to get links from your competitors.
Relevant Authority is a theory that the value that a page holds in the SERPs is indicative of the authority it holds for link equity in that term.
While there is no direct evidence that this is the case, it makes sense that a page gathering quality inbound links, based around certain anchor text, and holding content relevant to the vertical would pass a good amount of value. The best way to use the SERPs as a tool however is as a roadmap to quality links, and not as a direct line.
Alexa Traffic Info for the Domain
Quick Tip: Compete.com is just as good. The reality here is you are trying to correlate estimated value with actual visitor value. Is the site functioning or are you being duped?
Search engines do not take into account Alexa ranking and it does not make the link more valuable. This is an evaluation metric alone, NOT a value metric assigned by the engines to a link.
Alexa Ranking is a metric a lot of us hate. However, competitive traffic data has value in link evaluation. Often link partners will try to pass of networked pages as high quality link sources. They simply point a bunch of pages they own towards another page, up the link count, and offer a trade. One way to verify the quality of a page is competitive traffic data. If the site is actually getting a good amount of links it will have the traffic to back it up.
Is the Page Indexed?
Quick Tip: Check the index for the page. If you can’t find it check the robots.txt and the Meta robots tag for indications of exclusion.
The concept can be argued whether your link will ever be found and how much equity it can pass. For me time is money, and it is better spent on links that have 100% benefit and not theoretical benefit.
Are the links followed?
Quick Tip: Keep an eye on the “follow/nofollow” debate as it grows. Early results show little change in the way the engines are handling the attribute, but that could change.
Simply put, a link carrying the “nofollow” attribute is going to have little value in your portfolio beyond adding to its natural composition.
Hub Authority of Link Page
Quick Tip: In your competitive research you should be monitoring the similar links of your competition and obtaining said links. Use the SEOBook.com Hubfinder as a tool when auditing your own links and your competition.
A hub is central point in a series of hyperlinked documents. Often times a quality document will link out to several resources. This document is prime real estate for a link.
However, the real power is harnessed in the sites getting links from multiple hubs in a vertical. These are “authority” sites in the Hub Authority concepts, and a link from one of these documents will give you relevance and page authority.
Quick Tip: Avoid areas that are universally known for link abuse such as “link” or “resource” pages and template footers.
Link placement, as Jordan Kasteler noted, is one of the most overlooked metrics in SEO. Where your link is placed can have huge impacts on its value. This is largely due to concepts such as block level segmentation, where the engines are able to divide a web page by its pieces, and devalue links in certain areas.
Early on in SEO reciprocal linking was abused via “links” and “resource” pages eventually rendering these tools almost useless to the link builder. It was easy for the engine to devalue any document with the name links.html or resource.php.
The same has happened within the page architecture of documents as the engines are now able to use block segmentation to find the much abused footer of template sites i.e. WordPress installs.
A solid approach to link building is to take these metrics and create a matrix of link quality for your campaigns. Different verticals are going to require different metrics, but if you are able to create your quality goals at the outset of your campaign, and verify they are being met via audits, you will assure a higher quality link portfolio, and better overall ranking results.
Use this worksheet to evaluate your link profile.
Learn SEO Basics: Anchor Text of Inbound Links – SoloSEO.com
Understanding Link Authority and Trust – 97thFloor.com
Domain Authority and Misplaced Trust – SEOBook.com
How Many Links Per Page? – MattCutts.com
Domain Age: How Important is it for SEO? – SearchEngineJournal.com
Page Segmentation and Link Building – Huomah.com
Themes in Content: Hub and Authority Sites – SEOChat.com