Online relevance verification is performed to provide relevant advertisements to search queries received at a search engine. Relevance of an advertisement for a received search query is determined by comparing the content of a landing page associated with the advertisement against search results for the search query. Relevance may then be used to filter irrelevant advertisements from consideration and/or may be used in ranking advertisements during an auction process in conjunction with monetization factors. Selected advertisements may then be returned in response to the search query.