Some know their product, and some can use their point of sale materials well. But very few know how to convert facts and product points into benefits. Explain to your sales staff that if a particular feature of an item is in the item at the factory, or on the floor even before its sold, it is a product point. All three factors need one another. Without the supporting product point, the comment about better sleep is just an empty claim.
Good salespeople use both, but great salespeople add the dream, that is the vision of a better life.
The sales person who can enhance the value of a product does not have to negotiate price. All salespeople forget the basics and develop bad habits unless they are continuously trained in the basics. Do a critique of the sale, but remember, you are gathering information, you are not trying to give quick answers. Ask opinions, examine trouble spots. Promise to make adjustments, and follow through.