On April 29th, I wrote about customer feedback loops. Here are a few more thoughts.
Your customers will be amazed when they are transferred directly to an engineer that works on the product they are using. It is a very satisfying experience for your customers to establish a dialogue with more than just the customer service department. There is nothing so quite as satisfying as to have a direct impact and effect on a product that we use. Customers will give the people who build your products and services the best ideas for enhancements and new products. Also, consider placing some of your biggest and most important customers on a Customer Advisory Board and invite feedback from them on a regular basis.
Listen to your customers! Encourage and invite their feedback. They will tell you things that will never occur to you or anybody in your company.
Here is a great White Paper that may interest you.