In a complex universe, it is often reassuring to trust reliable and rational indicators. If ROI can be useful in certain cases, I agree with Jay: "Organizations pay senior executives handsomely to buy to their ability to make wise choices in the simple of absence measurements." Thus the systematic use of ROI is a nonsense, even an evasion of its responsibilities. Concerning social media marketing, some of my customers, marketing managers accustomed to the usual online campaigns, require "Ok, it’s a nice thing! But where’s the ROI ? ". I then use the concept developed by David Brown: The REAL Social Media ROI - Risk of Ignoring http://bit.ly/CTPo6