If you've developed the reflex of turning down your receipt every time you pop by over to McDonald's for a cheeky Big Mac, you may want to break the habit immediately. After making your order at McDonald's, don’t hesitate to ask for your receipt—it could be pretty important to you. A tastier burgerAccording to a former McDonald's employee on Quora, there are several secrets that make grant you a better experience each time to place your order. The most crucial of which is always insisting for a receipt. McDonald's employees are more attentive to clients who ask for a receipt and serve them the warmest and freshest possible burgers and fries.The reason?Mystery shopperSimple: if you ask for your receipt, McDonald's employees may think you could be a mystery shopper, meaning a customer paid by the company to try out the restaurant. Mystery shoppers always ask for a receipt so that they can be reimbursed later. After their visit, these mystery shoppers make a report about what they didn’t like so that the restaurant can improve on these weak points for normal customers. So don't be shy—always ask!