Builds Trust - Many times customers make a purchase and they are dissatisfied, but it's just too much work to return to the place of purchase. Has that ever happened to you? Very recently I purchased a headset with microphone from a giant retailer and after two or three uses one of the earbuds separated from the headpiece. I know that this retailer has a reputation for willingness to do exchanges or refunds so while it's aggravating I'm not unduly worried about it; I just have to make the time to return to the store. What is your return/refund policy if you are selling a product? Do your customers know your policy? Do you have any flexibility in your policy for long-standing customers? How about if you are a service provider? Do your customers know if they are unhappy with a service they can call you within a stated period? Although it may be unfair, small businesses and entrepreneurs seem to be held to a higher standard and while comments like "I bought an item from XYZ large retailer and it was not a good buy" will hardly affect that retailer, a similar comment about a small business can have a deadly effect.
It takes work, it takes scheduling, it takes time but by following-up after the sale, if there is any dissatisfaction and this is cheerfully addressed, you, the entrepreneur or small business owner, will have a loyal customer. That customer will trust you and want to do business with you time and time again.