It's best if they're all salespeople. One at a time, each of you tell about a customer from a sale you made. Select those who had outstanding success with your product or service. Be sure to include any trouble you had with the sale. Any reluctance to buy, previous bad experience, etc.
Great stories have highs and lows.
As each person finishes, the listeners ask questions about the sale. These questions represent information your listeners wanted, but your story didn't answer. You'll find these questions when answered enrich the story. You'll also notice one story will remind the group of other stories, each building on the other. After everyone's had their turn to tell and hear comments about their sale, retell each sales story with the additions inspired by your listeners questions and their stories.