There is nothing more tedious than being trapped in a meeting room while a sales person rolls off an endless series of features - it is extremely hard to contextualise the importance of any feature and extrapolate that into ROI for your business.
"Telling stories" through case studies is cited here as a good way to communicate the value of a product. I agree that this is a good approach but it's not a silver bullet. The best sales guys I've ever worked with really listen to their contacts, try get inside a clients head to understand what they are trying to achieve and then build a scenario (which they could back up with a patchwork of case studies) that solved a real, understood problem for their customer.
According to the Gartner survey, the best way for your reps to articulate value is to share customer stories. Some 70% of these executive buyers, for example, felt that "customer stories and case studies are the best way that providers can communicate differentiation that I trust." Stories work because they allow your customer to take your product out for a virtual test drive. They also work because they make your product memorable. According to authors Chip and Dan Heath, for example, after a presentation, 63% of the audience remember stories, and only 5% remember statistics.