Pages like “Pricing” are among SparkToro's most-visited pages, Fishkin said, and Google surfaced the links by analyzing the clickstreams of billions of Chrome users.
“My interpretation is that Google uses the number of clicks on a page in the Chrome browser to determine the most popular or important URLs on a site, which it then uses to calculate which URLs to include in the Sitelinks feature,” Fishkin said in the blog.
Quality and relevant sites really matter
According to Talent, the document references a Google machine learning tool called Site Authority or Domain Authority, which evaluates a site's ability to be indexed in Google Search based on its relevance to a particular subject area or industry.
Google executives, including search advocate John Mueller, head of Google Search Relations, have publicly denied the idea. “We don't have a website authority score,” Mueller said in a video. Google itself has also denied claims that it maintains a website authority score.
“Domain authority, Chrome data, and the like have long been considered 'non-input' by Google,” Tallent said.
While SEO experts aren't surprised by domain authority's role in search, King said it's a reminder to brands that quality of content is more important than quantity for visibility in search results.
Popular sites get higher search rankings
The leaked documents suggest that Google measures clicks for its algorithmic rankings through its Navboost system, which has been in operation since 2005.
This means that even if a lesser known site contains great information, the site that Google considers to be popular may receive a higher search rank for your query.
According to King, Navboost fine-tunes search results by promoting or demoting links using features such as goodClicks, badClicks and lastLongestClicks.
However, Google representatives have previously said that clicks are not used to rank sites.
Small website disruptions
King said the document also shows that search isn't set up to favor small sites: A feature called smallPersonalSite shows that Google isn't promoting small personal sites and blogs.
Smaller publishers have previously expressed concern that they have “virtually disappeared” from search results, with HouseFresh noting that its search traffic has fallen by 91% in recent months.
Learning on external devices
The document mentions using data from external devices such as Chromecast for Google searches, but it is not fully understood how this data will be used.
“This is a document about Google's search engineering,” Tallent said, “that shows that Google is using external device data and storing this information to help make search decisions.”