Giving something extra in business

When we buy a product or commodity in a super market, if the vendor or shop owner gives you something extra or chocolates free - psychologically we tend to go to the same shop to buy in the same shop. Same thing applies to every business.

If you are running a business, give something extra and free to the customer, whenever he drops by - that makes the customer loyal to you and he/she will just come to your shop and nowhere.