Advertising is often about "building brand awareness". You can't be sure that there is an acceptable ROI, just an expectation that there will be. Often compan

Advertising is often about "building brand awareness". You can't be sure that there is an acceptable ROI, just an expectation that there will be. Often companies will burn through investors' money trying to reach "critical mass". But no ad agency is going to dissuade the client management's false expectations. It's often said "half the money spent on advertising doesn't work ...", e.g. http://staff.washington.edu/gray/misc/which-half.html http://staff.washington.edu/gray/misc/which-half.html