The term "Moneyball approach" has been thrown around carelessly for the past five years or so. It has come to signify everything from using data and analytics to evaluate players to being clever in the transfer market, buying low and selling high.
Many clubs will tell you that they do both, though to what degree it's true is somewhat debatable. Some do have a closet full of nerds poring over spreadsheets and computer models, though it's unclear whether the decision-makers actually listen to them and whether their analytics are worth heeding (the field is still in its infancy, data is not as complete as it could be and some have gone up some blind alleys.