Abstract: Apparatus and method for selecting at least one content item based on data analysis. In accordance with some embodiments, a plurality of linked web pages of a website are defined by a publisher. Each web page has a respective layout which includes associated content and at least one slot adapted to receive a content item. A total number of web pages visited by each device of the website during an associated device session in which the device requests display of one or more of the web pages on a network accessible device is accumulated. At least one content item is transferred for display on the device during each said device session. A revenue amount is identified to the publisher from said displayed content items for each different total number of web pages visited during said device sessions.