One of the truly insidious aspects of public relations measurement is the use of advertising value equivalency (AVEs) or media value to assign financial value to public relations outputs. It is a highly flawed, path-of-least-resistance attempt to calculate return on investment (ROI) for public relations. To make matters worse, the practice has clearly moved into social media measurement as well. For example, research studies that attempt to monetize the value of a Facebook Fan/Liker by attributing a CPM value from the advertising world. Online media impact rankings also utilize equivalent paid advertising costs to assign monetary value to online news and social media. AVE is like a disease that has infected and spread throughout the public relations industry.
I've talked to a number of people lately trying to fight the AVE battled against entrenched marketing dinosuaurs who refuse to give it up. This should help