A first plurality of data points related to visitors to at least one website is received. The data points comprise at least an identification of the visitor and an interaction of the visitor with the website. A target audience comprising at least some of the visitors having a known, desired interaction and a plurality of selection rules defining tolerances for a similarity audience are received. The selection rules include a correlation score and an audience composition index. A similarity audience from a plurality of clusters defined by a number of unique visitors is selected wherein at least some of the unique visitors share at least one interaction in common, and the similarity audience comprises at least one cluster of the plurality of clusters satisfying the plurality of selection rules. Digital content is generated for electronic transmission to a plurality of computing devices associated with members of the similarity audience.