In a method of and an apparatus for determining a portion of total costs of each entity of a plurality of entities, a maximum value related to a maximum number of accesses of each entity in a time window over a time interval is obtained. Then, the smallest or highest maximum value among the entities is found. The total costs for the smallest maximum value are equally divided among all entities having access to the product in the time interval. Then, a next-higher maximum value among the entities has to be found, and the different costs relating to the next-higher maximum value are determined and equally distributed among the entities having the same or a higher maximum value than the next-higher value. The steps of finding and distributing are repeated until all maximum values are processed. Then, the costs obtained in the steps of distributing are accumulated for each entity.