Are salespeople expected to have super-natural abilities?

From a straight economics point of view, a store can be overpriced because sales people deliver services that are worth paying more to utilize. Those services are honest advice about what a customer needs and the convenience of getting it right then from someone who is trustworthy. That's why you go to a store instead of the internet. The biggest concern of brick and mortar stores is that people will come and talk to the sales people and then buy on the internet. Some stores, like Circuit City, tried to cut their sales staff budget and went bankrupt. Others, like Best Buy, improved their knowledgeable staff and are still going strong competing with online sales. Best Buy shows what a sales person needs to do. They need to know the products, know the customers, and match the customers needs to the products that fill them. Don't worry about your competition, just advise the customer about how your store can best help them. If you do that, people will pay for the value of your services by buying from your store.