Abstract: A marketing segment rule for access by both a real-time component and a back end component may be stored. The real-time component may be configured to qualify a visitor to network content in a marketing segment during the visitor's visit to the network content. The back end component may be configured to qualify the visitor in the marketing segment after the visitor's visit to the network content. Qualification of a first visitor in a marketing segment may be determined. Such a determination may include evaluating network content data for the first visitor according to the marketing segment rule. An indication of the first visitor's segment qualification may be stored. An online advertisement may be presented to the first visitor based on the first visitor's segment qualification.

Abstract: Selection of a trait may be received. A complex segment rule may be created that is usable to evaluate one or more qualification events. For example, the segment rule may be usable to evaluate a combined recency and frequency of the one or more qualification events. The qualification events may be based on collected network data associated with the plurality of visitors with each qualification event corresponding to a separate qualification of visitor according to the trait. The qualification events may be evaluated together according to the segment rule. For example, the combined recency and frequency of the one or more qualification events may be evaluated according to the segment rule. Evaluating the segment rule may include estimating a segment population size in real-time.