Advertisements in a social networking system may be targeted to searching users in relation with a real-time search engine operated by a social networking system. Ads are targeted to users based in part on social information included in a structured search query and/or search results on a page. In a typeahead search, a user of the social networking system may receive prefix search results of objects in the search box. The prefix search results are ranked by relevance to the user, and advertisers may bid for particular objects to increase their ranking in the results list. An option may be provided to a viewer of search query results to buy an ad that would be seen by other users who performed the same search query, received a targeted search result, or based on targeting criteria as determined by the viewer bidding on the ad.