or more query terms and an additional one or more constraint terms the entertainment item rating and selection engine selects a content item from the set of content items the selection may be random based on past user responses or responses of users belonging to particular clusters the entertainment item injector then replaces one of the search results or advertisements with the content item the content item is presented to the user on a search results page the content item contains a feedback mechanism to collect user responses the entertainment item rating and selection engine then derives the quality of the entertainment item from the collected user responses application_number US 96342307 A description in the following description for the purposes of explanation numerous specific details are set forth in order to provide a thorough understanding of the present invention it will be apparent however that the present invention may be practiced without these specific details in other instances well known structures and devices are shown in block diagram form in order to avoid unnecessarily obscuring the present invention currently when a user performs a search using a commercial search engine the search engine returns a set of results and relevant advertisements the results are presented in a layout which is similar across all search engines the layout consists of a banner advertisement and search engine input box at the top of the page navigation at the bottom of the page text advertisements on the right of the page and a list of results on the left side of the page the search results and sometimes the advertisements are based on user submitted query terms in one embodiment of the invention a page presenting the search results is altered at certain periods of time in the following manner one of the.