They list their needs in RFP documents that are hundreds of pages in length. They hire consultants to verify that they are making the right decisions. They'll conduct lengthy product evaluations and talk to existing users of the products to ensure they work as advertised. All these steps are taken in an effort to eliminate their fears, reduce their uncertainties, and satisfy their doubts. However, customers are never 100 percent sure they are purchasing the right product and there are always naysayers in the organization who are against moving forward. As a result, customers frequently won't make a purchase even after an exhaustive evaluation. Get the full story at Harvard Business Review