Kevin Lang (langk@yahoo-inc.com), Joaquin Delgado (jdelgado@yahoo-inc.com), Dongming Jiang, Bhaskar Ghosh, Shirshanka Das, Amita Gajewar, Swaroop Jagadish, Arathi Seshan, Chavdar Botev, Michael Binderberger-Ortega, Sunil Nagaraj, Raymie Stata Efficient Online Ad Serving in a Display Advertising Exchange