By Kelly Grainger, CreoLogic Design Inc.
87. Linking Domain Age: Backlinks from aged domains may be more powerful than new domains.
88. # of Linking Root Domains: The number of referring domains is one of the most important ranking factors in Google’s algorithm, as you can see from this industry study of 1 million Google Search results.
89. # of Links from Separate C-Class IPs: Links from separate class-c IP addresses suggest a wider breadth of sites linking to you, which can help with rankings.
90. # of Linking Pages: The total number of linking pages — even from the same domain — has an impact on rankings.
91. Backlink Anchor Text: As noted in this description of Google’s original algorithm:
“First, anchors often provide more accurate descriptions of web pages than the pages themselves.”
Obviously, anchor text is less important than before (and, when over-optimized, work as a webspam signal). But keyword-rich anchor text still sends a strong relevancy signal in small doses.
92. Alt Tag (for Image Links): Alt text acts as anchor text for images.
93. Links from .edu or .gov Domains: Matt Cutts has stated that TLD doesn’t factor into a site’s importance. And Google has said they “ignore” lots of Edu links. However, that doesn’t stop SEOs from thinking that there’s a special place in the algorithm for .gov and .edu TLDs.
94. Authority of Linking Page: The authority (PageRank) of the referring page has been an extremely important ranking factor since Google’s early days and still is.
95. Authority of Linking Domain: The referring domain’s authority may play an independent role in a link’s value.
96. Links From Competitors: Links from other pages ranking in the same SERP may be more valuable to a page’s ranking for that particular keyword.
97. Links from “Expected” Websites: Although speculative, some SEOs believe that Google won’t fully trust your website until you get linked to from a set of “expected” sites in your industry.
98. Links from Bad Neighborhoods: Links from so-called “bad neighborhoods” may hurt your site.
99. Guest Posts: Although links from guest posts still pass value, they likely aren’t as powerful as true editorial links (plus, “large-scale” guest posting can get your site into trouble).
100. Links From Ads: According to Google, links from ads should be nofollowed. However, it’s likely that Google is able to identify and filter out followed links from ads.
101. Homepage Authority: Links to a referring page’s homepage may play special importance in evaluating a site’s — and therefore a link’s — weight.
102. Nofollow Links: This is one of the most controversial topics in SEO. Google’s official word on the matter is:
“In general, we don’t follow them.”
Which suggests that they do… at least in certain cases. Having a certain % of nofollow links may also indicate a natural vs. unnatural link profile.
103. Diversity of Link Types: Having an unnaturally large percentage of your links coming from a single source (ie. forum profiles, blog comments) may be a sign of webspam. On the other hand, links from diverse sources is a sign of a natural link profile.
104. “Sponsored Links” Or Other Words Around Link: Words like “sponsors”, “link partners” and “sponsored links” may decrease a link’s value.
105. Contextual Links: Links embedded inside a page’s content are considered more powerful than links on an empty page or found elsewhere on the page.
106. Excessive 301 Redirects to Page: Backlinks coming from 301 redirects dilute some PageRank, according to a Webmaster Help Video.
107. Internal Link Anchor Text: Internal link anchor text is another relevancy signal. That said, internal links likely have much less weight than anchor text coming from external sites.
108. Link Title Attribution: The link title (the text that appears when you hover over a link) may also be used as a weak relevancy signal.
109. Country TLD of Referring Domain: Getting links from country-specific top level domain extensions (.de, .cn, .co.uk) may help you rank better in that country.
110. Link Location In Content: Links in the beginning of a piece of content may carry slightly more weight than links placed at the end of the content.
111. Link Location on Page: Where a link appears on a page is important. Generally, a link embedded in a page’s content is more powerful than a link in the footer or sidebar area.
112. Linking Domain Relevancy: A link from a site in a similar niche is significantly more powerful than a link from a completely unrelated site.
113. Page-Level Relevancy: A link from a relevant page also passes more value.
114. Keyword in Title: Google gives extra love to links from pages that contain your page’s keyword in the title (“Experts linking to experts”.)
115. Positive Link Velocity: A site with positive link velocity usually gets a SERP boost as it shows your site is increasing in popularity.
116. Negative Link Velocity: On the flip side, a negative link velocity can significantly reduce rankings as it’s a signal of decreasing popularity.
117. Links from “Hub” Pages: The Hilltop Algorithm suggests that getting links from pages that are considered top resources (or hubs) on a certain topic are given special treatment.
118. Link from Authority Sites: A link from a site considered an “authority site” likely pass more juice than a link from a small, relatively unknown site.
119. Linked to as Wikipedia Source: Although the links are nofollow, many think that getting a link from Wikipedia gives you a little added trust and authority in the eyes of search engines.
120. Co-Occurrences: The words that tend to appear around your backlinks helps tell Google what that page is about.
121. Backlink Age: According to a Google patent, older links have more ranking power than newly minted backlinks.
122. Links from Real Sites vs. “Splogs”: Due to the proliferation of blog networks, Google probably gives more weight to links coming from “real sites” than from fake blogs. They likely use brand and user-interaction signals to distinguish between the two.
123. Natural Link Profile: A site with a “natural” link profile is going to rank highly and be more durable to updates than one that has obviously used black hat strategies to build links.
124. Reciprocal Links: Google’s Link Schemes page lists “Excessive link exchanging” as a link scheme to avoid.
125. User Generated Content Links: Google can identify UGC vs. content published by the actual site owner. For example, they know that a link from the official WordPress.com blog is very different than a link from besttoasterreviews.wordpress.com.
126. Links from 301: Links from 301 redirects may lose a little bit of juice compared to a direct link. However, Matt Cutts says that a 301s are similar to direct links
127. Schema.org Usage: Pages that support microformats may rank above pages without it. This may be a direct boost or the fact that pages with microformatting have a higher SERP CTR:
128. TrustRank of Linking Site: The trustworthiness of the site linking to you determines how much “TrustRank” gets passed on to you.
129. Number of Outbound Links on Page: PageRank is finite. A link on a page with hundreds of external links passes less PageRank than a page with a handful of outbound links.
130. Forum Links: Because of industrial-level spamming, Google may significantly devalue links from forums.
131. Word Count of Linking Content: A link from a 1000-word post is usually more valuable than a link inside of a 25-word snippet.
132. Quality of Linking Content: Links from poorly written or spun content don’t pass as much value as links from well-written, content.
133. Sitewide Links: Matt Cutts has confirmed that sitewide links are “compressed” to count as a single link.
