Engaged employees produce better business outcomes -- across industries, company sizes and nationalities, and in good economic times and bad. Business or work units that score in the top quartile of their organization in employee engagement have nearly double the odds of success. Those at the 99th percentile have four times the success rate of those at the first percentile.

So, who's behind these bizarre assertions? Gallup, and they have the receipts.

How does Gallup define ‘success’? It's a composite of financial, customer, retention, safety, quality, shrinkage and absenteeism metrics.

How does Gallup define ‘engagement’? It's based on the employees' answers to survey questions on business-/work-unit profitability, productivity, employee retention and customer perception.