This paper discusses the potential of a multi-media single source data base containing audience estimates collected with passive persons meters which detect audio encoded material and product purchase. "Real world" tests are discussed. Technical aspects, such as persons passive meters, Internet and CD ROM usage without wiring into the computer are described. A feature which gathers information product purchases at movies, airlines, mom and pop stores and fast food chains are explained. Some additional uses including proof of performance, billing and payment are suggested. Advertiser accountability, the ability to quantify the sales impact of advertising, consumer and trade promotion and quality media measurement can be achieved with this system at lower costs.