A network server includes a webpage provider, a user monitor, and a content selector. The webpage provider is configured to provide to a user terminal a webpage including a first region and a second region arranged in a first direction in response to a request from the user terminal. The first region includes pieces of first content arranged in a second direction crossing the first direction, and the second region includes pieces of second content arranged in the second direction. The user monitor is configured to detect an action of the user terminal for the pieces of first content. The content selector is configured to search for pieces of third content related to the content for which the action of the user terminal is detected among the pieces of first content in a database, and to include the pieces of third content in the second region.