See That Billboard? It May See You, Too - The New York Times

A beacon of hope for billboard advertising

"Clear Channel Outdoor Americas, which has tens of thousands of billboards across the United States, will announce on Monday that it has partnered with several companies, including AT&T, to track people’s travel patterns and behaviors through their mobile phones.

By aggregating the trove of data from these companies, Clear Channel Outdoor hopes to provide advertisers with detailed information about the people who pass its billboards to help them plan more effective, targeted campaigns. With the data and analytics, Clear Channel Outdoor could determine the average age and gender of the people who are seeing a particular billboard in, say, Boston at a certain time and whether they subsequently visit a store."

See That Billboard? It May See You, Too - The New York Times