No, they cannot. They are financially and emotionally dependent on their product. They are not free, they are biased, so their copy has no effect on buyers. Even in the best, and rather rare, case where sellers know their customers' true motivations for buying or ordering, they fail to use this knowledge effectively in their advertising. The reason for this is that salespeople themselves have not selected their product among competing products, have not made the purchase decision, and do not have the cognitive and emotional experience of the buyer. Sellers fantasize about their product, buyers read or listen with skepticism and pass them by.