Share the stories and experiences of those pleased with your product or services. If you've delivered on your promise to your customer, get their feedback in writing. As you wrap up with your customer, ask them if they'd take a moment to give you some honest feedback on their experience with you. If it's positive, you'll be able to share those comments with others who may be interested in using your type of service or working with you in particular. If it's negative, you have something concrete you can review to improve your services.