The document discusses eight levels of user engagement with social networks and other digital media based on an existing model developed by the Advertising Research Foundation. The eight levels include: 1) vehicle distribution, 2) vehicle exposure, 3) advertising exposure, 4) advertising attentiveness, 5) advertising communication, 6) advertising persuasion, 7) advertising response, and 8) sales response, with each level building on the previous ones to represent increasing levels of user engagement with advertising and brands. The model provides a framework for understanding how users interact with both digital and traditional media.