Have you ever put on a jacket when the seasons changed and found money in the pocket from last year?  How exciting was that?  It's not that the $5 you found will make or break you, but it seems like you're getting free money because you weren't expecting it.  You likely told several of your friends about your good fortune.

Wouldn't it be great if you could get your customers to talk to their friends about your business with the same enthusiasm?   The principle is the same:  give them more than they expect, and they will spread the word.  Word-of-mouth is the primary factor behind 20 - 50% of all purchasing decisions, particularly when a consumer is buying a product for the first time or when the product is expensive.[i]   The growth of social networking has made word-of-mouth even more important because prospective customers can hear about your products and services from anyone in the world, at any time of day, and without ever leaving the comfort of their homes.

Years ago, there was a factory near my home that made kitchen utensils.  As do many manufacturers, they sold the products that hadn't quite measured up to their standards through an outlet store located in the factory.  Everyone I knew shopped there because not only did you get a deep discount price on merchandise that was only slightly defective, you also got a surprise in your bag every time you visited.  For example, if you went into the outlet store to buy cookie sheets, you might get them at 50% off because someone had dropped them and dented the edges.  But when you got home and opened up the bag, you would find that the cashier had put in a little something extra - maybe a spatula or a cookie cutter.  Usually it was something you didn't consider essential, but it was free, making you perceive it as very valuable. 

When you go to an outlet store, you expect to find great bargains on the things you pick out, but the manufacturer had figured out that if he gave you more than the bargain you expected, you would keep coming back.  He unloaded his defective merchandise, saving himself the cost of hauling it away as trash, simply by giving away something that probably cost him only pennies to make.  The gift further reduced his inventory of defective merchandise because it also came from the seconds bin.

The same principle applies to service.  For example, when you take your car in for an oil change, you expect the garage to change the oil and filter.  But what if they also check the level of all the fluids and top them off?  It costs them virtually nothing to add a few ounces of windshield washer fluid, power steering fluid, and antifreeze, but it gives you peace of mind and builds loyalty by beating the your expectations.  In addition, while the mechanic is checking fluid levels, he may find another engine problem that the sales associate can point out to the customer, further improving the customer's perception that he is receiving an added value and possibly increasing the amount of revenue from that customer's visit to the garage.