“We all know that the days of easily calculated return on investment are years, if not decades, behind us. The once-simple formula, which compared how much a brand spent on an ad campaign to how many people it reached, has been replaced with new math for our digital age. While the temptation might be to keep counting clicks, eyeballs, likes and retweets (or some combination) and call it an assessment of success, consumers have become way too savvy for purely quantitative measures to matter much.”