“Google’s Popularity signal (P*) ‘uses Chrome data’ to capture the popularity of websites. The signal is a measure quantifying the number of links between pages, as reflected in anchor text and user interactions, and it is used to promote well-linked documents.”

In the DOJ v. Google remedial opinion, the court revealed that Google’s Popularity signal (P*) is one of the company’s fundamental top-level ranking signals, alongside quality. While Google has long emphasised PageRank as its primary authority signal, the opinion shows that Popularity (P*) draws on Chrome browsing data and the number of anchors (link connections between pages) to measure how “well-linked” and widely visited a page is. This detail was not available in the original trial exhibits, which only contained a redacted line noting a “popularity signal that uses Chrome data.” The fuller explanation – including anchors and the role of promoting well-linked documents — only emerged later in the unredacted remedial opinion. This makes P* a core mechanism by which Google evaluates and elevates content in search results, and demonstrates how user browsing data feeds directly into ranking.

In the DOJ v. Google remedial opinion, the court identified Quality as one of Google’s fundamental top-level ranking signals, paired with Popularity. Quality is described as being derived largely from the webpage itself, supplemented by inputs such as PageRank (distance from known authoritative sources), spam scores, and human rater evaluations. In the original trial exhibits, much of this section was blacked out under “Highly Confidential Information” protections, leaving only partial references to PageRank and generic mentions of a “quality score.”

The later unredacted remedial opinion confirmed that Quality incorporates signals of authoritativeness, content-derived metrics, and rater scoring, and is directly used in determining a page’s ranking. This disclosure highlights Quality as a systemic scoring function — not just an abstract concept — and underscores its central role in shaping search results.

What This Means

Chrome Visit Data → The signal directly taps into browsing behaviour from Google Chrome, giving Google visibility into what users are visiting across the web.
Anchor Link Structures → It measures how pages are connected by links, including anchor text relevance.
User Interaction Data → Beyond static link graphs, it incorporates behavioural evidence of popularity from actual user navigation.
Promotion of Well-Linked Documents → Pages with stronger link connectivity and demonstrated popularity are pushed higher in ranking.

SEO Relevance

This is a significant confirmation because:

It ties Chrome browsing data directly into organic ranking (something Google has denied or downplayed publicly).
It shows popularity is not just PageRank, but a broader signal combining Chrome data + anchor link structures + user behaviour.
It acts as a boost mechanism for documents seen as “well-linked” both by hyperlink structure and user engagement.

Evidence Brief

DOJ v. Google – Case No. 20-cv-3010 (Remedial Phase Opinion)
Full Court PDF

1. Popularity as a Top-Level Signal

“Google has developed various ‘top-level’ signals that are inputs to producing the final score for a web page… Among Google’s top-level signals are those measuring a web page’s quality and popularity.”
View in PDF (Page 141)

2. Popularity & Quality Guide Crawling Frequency

“Quality and popularity signals, for instance, help Google determine how frequently to crawl web pages to ensure the index contains the freshest web content.”
View in PDF (Page 142)

3. Plaintiffs Sought Disclosure of Popularity (via Navboost/Glue)

“They are ‘popularity as measured by user intent and feedback systems including Navboost/Glue’ and ‘quality measures including authoritativeness’ associated with each DocID.”
View in PDF (Page 146)

4. Popularity = Chrome Data + Anchors

“Two exhibits suggest that popularity is based on ‘Chrome visit data’ and ‘the number of anchors,’ which is a measure that quantifies the number of links between pages and is used to promote well-linked documents. See PXR0171 at -095 to -098; PXR0356 at -744 (popularity signal (P*) ‘uses Chrome data’).”
View in PDF (Page 147)

5. Popularity & Quality as Fundamental Ranking Signals

“Compare… describing popularity and quality as ‘fundamental ranking signals.’”
View in PDF (Page 145–146)

Key Takeaways

Popularity (P*) is a top-level, fundamental ranking signal.
It is explicitly linked to Chrome visit data (browser-based user behaviour).
It also uses the number of anchors (link graph measure of interconnectivity).
Purpose: Promote “well-linked documents” in ranking.
Crawling frequency is guided by popularity and quality.
Plaintiffs specifically tried to force disclosure of popularity measures tied to Navboost/Glue.