Hal Varian, Google's chief economist, explains how the AdWords auction works.
See more here: https://www.youtube.com/watch?v=5ZnWq0XMClc
Source: https://drive.google.com/open?id=0B2TXQ9U3oFDJWU4tS3JwVTlXUUk
See more here: https://www.youtube.com/watch?v=5ZnWq0XMClc