1. A method for comparing purchase patterns, comprising: matching a plurality of products purchased by a base company to a plurality of leaf nodes in a taxonomy tree to obtain a plurality of matching leaf nodes, wherein the taxonomy tree is a hierarchical classification of products; assigning, to each of the plurality of matching leaf nodes and to each parent node of the plurality of matching leaf nodes, a point value to obtain a plurality of point values; creating, for the base company and by a computer processor, a base feature vector comprising the plurality of point values; calculating, by the computer processor, a similarity score between the base feature vector of the base company to a test feature vector of a test company; and providing, in response to the similarity score satisfying a similarity threshold, a recommendation, wherein the recommendation comprises an advertisement to a customer of the base company.