Information Gain

What is Information Gain?

Information gain is the amount of new, useful information a piece of content provides beyond what other sources on the same topic already contain. A page with high information gain adds facts, data, examples or perspectives the reader has not encountered elsewhere. A page with low information gain mostly repeats the consensus found in other top results.

In machine learning, “information gain” has an older, technical meaning related to entropy in decision trees. In SEO, the term took off after Google was granted a patent titled “Contextual estimation of link information gain” (filed October 2018, granted June 2022). The patent describes scoring how much additional information a document holds beyond documents the user has already seen, then using that score to choose what to show next.

How it works

The patent’s core idea, simplified:

1. Track what the user has seen. A system notes documents already viewed for a topic or session.
2. Compare new candidates. For each unseen document, estimate the information it contains beyond those already viewed.
3. Score and rank. Documents with more novel information receive a higher information gain score and may be promoted.

Google has not said whether, or how, this is used in Search. What Google has published is guidance in its helpful content documentation, which asks whether content provides “original information, reporting, research, or analysis” and “substantial value when compared to other pages in search results.” Practitioners use “information gain” as shorthand for that standard.

From SEO to AEO and GEO

Classic SEO workflows often encouraged sameness: analyze the top ten results, cover every subtopic they cover, match their length. That produces pages that are complete but interchangeable.

AI answer engines raise the cost of sameness. Systems such as Google AI Mode use query fan-out to gather many sources, then synthesize one answer. If ten pages say the same thing, the engine needs only one of them, and it may prefer a well-known domain. The pages that earn a distinct citation are the ones contributing something the others lack, such as a number, an example or a first-hand finding.

Classic SEO habit	AEO/GEO priority
Match competitor coverage	Add what competitors lack
Longer is safer	Specific is safer
Summarize consensus	Contribute evidence

What carries over: covering the basics and matching intent. What changed: covering the basics is the entry ticket, not the differentiator.

What to do about it

1. Run a novelty check before publishing: list what top results and AI answers already say, then write down what your page adds. If the list is empty, rethink the piece.
2. Mine internal sources: support tickets, sales call notes, implementation docs and product data (aggregated and anonymized).
3. Publish original data with methodology, even small studies, so others can cite them.
4. Add expert specifics: real configurations, edge cases, failure modes and trade-offs from practitioners.
5. Label clearly. Put the novel finding in a quotable sentence near the top of a section.
6. Refresh with new information, not just a new date.

Common mistakes

• Rewording competitors and calling it original.
• Inventing statistics to look novel. Fabricated data damages trust with readers and engines.
• Hiding the unique insight deep in a long article.

Related terms

• Content Quality
• E-A-T
• Thin Content
• Query Fan-Out
• AI-Generated Content
• Topical Authority
• How AI engines cite sources

Sources

• Contextual estimation of link information gain (US11354342B2), Google Patents
• Creating helpful, reliable, people-first content, Google Search Central
• AI features and your website, Google Search Central