What is Information Gain in content creation and how do I measure it for AI ranking?

Information Gain measures whether your content adds new knowledge to the search index or simply repeats existing consensus. The formula is: Information Gain = (Total Information in Document B) - (Information User Already Consumed in Document A). To measure it: 1) Audit top-ranking content for your target query, 2) Identify what information is missing, outdated, or shallow, 3) Add original data, unique frameworks, expert quotes, or case studies, 4) Use tools like RivalFlow AI or Infranodus to compare your content depth against competitors. According to Forrester 2026 research, content with high Information Gain ranks 3x higher in AI responses.