The best way to sell is to show. The less you have to explain, the more you have to demonstrate. People can be sold by words, but when they can see or feel what you are selling, you won’t have to say anything.
Example: I’m selling one of my old cameras, and a friend who was interested in it today asked me about it. Instead of explaining features, I offered to let her borrow it and take pictures. Now I don’t have to try to convince her of anything. If it’s a good fit, she will know, and she will buy it. If it’s not, I would have done a disservice by convincing her to buy it.
Example 2: Some pet adoption centers allow you to take a dog home for a week-long test period before committing to the purchase. I’m sure it’s difficult to return a puppy that has been part of your family for a week.