41. Reading Level
There’s no doubt that Google estimates the reading level of webpages:
But what they do with that information is up for debate. Some say that a basic reading level will help your page rank because it will appeal to the masses. However, Linchpin SEO discovered that reading level was one factor that separated quality sites from content mills.
42. Affiliate Links
Affiliate links themselves probably won’t hurt your rankings. But if you have too many, Google’s algorithm may pay closer attention to other quality signals to make sure you’re not a “thin affiliate site”.
43. HTML errors/WC3 validation
Lots of HTML errors or sloppy coding may be a sign of a poor quality site. While controversial, many in SEO think that WC3 validation is a weak quality signal.
44. Page Host’s Domain Authority
All things being equal a page on an authoritative domain will higher than a page on a domain with less authority.
45. Page’s PageRank:
Not perfectly correlated. But in general higher PR pages tend to rank better than low PR pages.
46. URL Length
Search Engine Journal notes that excessively long URLs may hurt search visibility.
47. URL Path
A page closer to the homepage may get a slight authority boost.
48. Human Editors:
Although never confirmed, Google has filed a patent for a system that allows human editors to influence the SERPs.
49. Page Category
The category the page appears on is a relevancy signal. A page that’s part of a closely related category should get a relevancy boost compared to a page that’s filed under an unrelated or less related category.
50. WordPress Tags:
Tags are WordPress-specific relevancy signal. According to Yoast.com :
“The only way it improves your SEO is by relating one piece of content to another, and more specifically a group of posts to each other”
51. Keyword in URL
Another important relevancy signal.
52. URL String
The categories in the URL string are read by Google and may provide a thematic signal to what a page is about.
53. References and Sources
Citing references and sources, like research papers do, may be a sign of quality. The Google Quality Guidelines states that reviewers should keep an eye out for sources when looking at certain pages: “This is a topic where expertise and/or authoritative sources are important…”.
54. Bullets and Numbered Lists:
Bullets and numbered lists help break up your content for readers, making them more user friendly. Google likely agrees and may prefer content with bullets and numbers.
55. Priority of Page in Sitemap
The priority a page is given via the sitemap.xml file may influence ranking.
56. Too Many Outbound Links
Straight from the aforementioned Quality rater document:
“Some pages have way, way too many links, obscuring the page and distracting from the Main Content”
57. Quantity of Other Keywords Page Ranks For:
If the page ranks for several other keywords it may give Google an internal sign of quality.
58. Page Age
Although Google prefers fresh content, an older page that’s regularly updated may outperform a newer page.
59. User Friendly Layout:
Citing the Google Quality Guidelines Document yet again:
“The page layout on highest quality pages makes the Main Content immediately visible”
60. Parked Domains :
A Google update in December of 2011 decreased search visibility of parked domains.