Let's start out by my telling you that I know my mattresses inside and out, but I don't know your comfort needs. With your cooperation we can find that out in a hurry. Nothing always works in sales because each customer is different, in spite of the fact that a customer is a customer. That's the challenge in selling and that's why I've never met a dull-minded salesperson who excelled at selling. Degrees don't necessarily guarantee success in selling, or in any other career for that matter, but smarts are another matter.
All successful salespeople are smart.
They all learn to let go of what doesn't work for them. The others keep on practicing what's wrong. All salespeople are not the same. That's why customers go from store to store until they find a salesperson. By the way, it's just as wrong to say all customers are the same.