Long ago, in a world far, far away, brands made ads and put them on TV. People watched these ads. Not because they wanted to, but because they lacked a device called a “remote” – never mind time shifting DVRs. The theory was that if consumers sat there long enough and were exposed to enough ad impressions, some degree of positive behavior would ultimately ensue.
Robert Passikov is dead on in his analysis about why brands are still wringing their hands about social media measurement. They still don't get it.