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.