A facility for identifying purchasing opportunities within a set of purchasing opportunities that are similar to a distinguished purchasing opportunity is described. The distinguished purchasing opportunity has descriptive information associated with it. For each of several terms occurring in this descriptive information, the facility generates a term score. Each term score reflects the extent to which the occurrence of the term and the descriptive information associated with the distinguished purchasing opportunity differentiates the distinguished purchasing opportunity from auto purchasing opportunities in the set. The facility then selects as key words the terms occurring in the descriptive information associated with the distinguished purchasing opportunity that have the highest term scores. The facility identifies purchasing opportunities of the set containing the selected key words, and establishes a purchasing opportunity score for each identified purchasing opportunity by summing the term score of the key words occurring in information associated with the identified purchasing opportunities.