In the past decade, the shift of advertising dollars to measurable digital marketing channels has suddenly made experiments an economically feasible way to inform marketing decisions such as how advertising should be designed and targeted, what types of promotions are most effective, what products should be offered, how sales staff should be compensated, which sales channels should be emphasized, etc. Elea McDonnell Feit gave a great workshop on how to do field experiments in digital marketing at WU Vienna.