A method and system for placement of graphical objects on a page to optimize the occurrence of an event associated with such objects. The graphical objects might include, for instance, advertisements on a webpage, and the event would include a user clicking on that ad. The page includes positions for receipt of the object material. Data regarding the past performance of the objects is stored and updated as new data is received. A user requests a page from a server associated with system. The server uses the performance data to derive a prioritized arrangement of the objects on the page. The server performs a calculation regarding the likelihood that an event will occur for a given object, as displayed to a particular user. The objects are arranged according to this calculation and returned to the user on the requested page. The likelihood can also be multiplied by a weighting factor and the objects arranged according to this product.