Abstract: Example methods, apparatus, and articles of manufacture to monitor audience exposure to media using duration-based data are disclosed. A disclosed example method involves determining a duration of exposure to an information medium based on transaction information associated with access to a public establishment, determining a first duration value based on the duration of exposure, and determining a second duration value indicative of a duration for which the information medium is accessible within the public establishment. The example method also involves determining an exposure performance value based on the first and second duration values indicative of an exposure performance of the information medium.