The document discusses the "click gap", which is a measure of how much more traffic a piece of content could potentially drive compared to the number of site visits it actually receives from searches. It examines the total searches for a keyword and compares it to the number of site entrances from those searches. The click gap exists because no single site receives traffic from 100% of searches on a keyword. Marketers can compete in the click gap by driving down clicks on competitors' sites, driving up no-clicks and clicks to their own content, showing up higher in search results, and making their content highly useful to users by explicitly answering search queries.