It is a myth that art has to be sold. It is not like stocking a grocery store where people fill a pushcart. Art is a product that has no apparent need. The salesperson builds the need in the mind of the buyer.

This quote is saying that selling art is different from selling grocery items. People do not usually go out to buy art because they need it in the same way that they need food from the grocery store. Instead, the salesperson has to create a need for the artwork in the mind of the buyer. This is done by emphasizing the beauty, craftsmanship, or sentimentality of the piece. They must find a way to make potential buyers feel like they must have the art in order to complete their home or otherwise enrich their lives.