Certainly not an advertising apologist, but sometimes advertising attempts to provide information to alter consumer behavior in a way that is more optimal for the consumer and the advertisng vendor than it is pessimal for the original vendor. From a mpg(society) perspective, some urban commuter might do far better in a Prius than in, say, a Suburban. This might be the result of advertising and also a net gain for society. Also, sometimes really good things get underwritten NPR, Podcasts, etc (which might be like advertising).