In this series of posts we are investigating strategic and tactical decision-making processes in common use today, versus optimized decision making processes to which we should be transitioning. Each brand has a personality and the creative agency is often referred to as the keeper of the brand personality. A significant part of the brand's appeal is its personality, although research has not identified the exact contribution that the personality – apart from habit, product characteristics, price and other factors – makes to sales, loyalty, and brand equity. As we enter the new era of ROI-based marketing for brand advertisers, it becomes essential to quantify everything in terms of ROI contribution.