A computer-implemented method and system for combining keywords into logical clusters that share a similar behavior with respect to a considered dimension are disclosed. Various embodiments are operable to order a list of keywords from high activity to low activity, partition the list into at least two sets, a head partition including keywords with an activity level above a predefined threshold, a tail partition including the remainder of the keywords in the list, model the keywords in the head partition based on a set of variables, score the keywords in the head partition based on the modeling, and cluster head partition keywords with tail partition keywords having at least one common variable into at least one keyword cluster.