Surprise rewards are great: they make people happier and more motivated. On the other hand, expected rewards are not as effective – they may even lead to lower levels of happiness, says psychology. Do you want to make your customers happy? Send them surprise coupons or deals. Avoid, though, running repeated promotions, such as offers valid every Thursday. Once you know how your audience thinks, what makes them tick, you can adjust your strategy to become more effective. Make sure that you use the right approach for your industry and target market, and that you always combine these strategies with the most effective weapon of all - amazing customer service.