Accessibility measures the potential of opportunities for interaction. This paper proposes and explores a new flow-based measure, 'place rank' using origin-destination information. Both impedance and value of opportunities are embedded in the dataset that includes the origin and destination of each person within the studied region. Individuals contribute to the place rank at their destination (work) zone with a power that depends on the attractiveness of the zone of origin. In this paper we demonstrate this place rank measure for three activities (Jobs, Resident Workers, and Health Services) in the Minneapolis-St. Paul metropolitan region and Jobs in Montreal, Canada. We compare place rank to traditional measures of accessibility. Since place rank is based on actual choices of origins and destinations it is a measure of realized rather than potential opportunities, and so unlike accessibility measures. Also it does not require the knowledge of travel time between all origins and destinations.