Apparatus and a method that control the number of sponsored links that are presented in search result webpages in response to a search string presented by a user, based on the past behavior of users to presentations of result in response to the same search string. When this past behavior indicates that users tend to select sponsored links, the number of sponsored links in the results sent to the user is increased, thereby a more responsive presentation. In addition to sending results with a controlled number of sponsored links, the apparatus and the method account for the response of the user so as to include the user's behavior in the information about past behavior of users.