I think it is very important for both parties to have a clear understanding of their obligations in a sales situation. Ultimately the buyer is in the position of power, and as a decision maker, they have a responsibility to themselves, or their organizations to do their due diligence. You’d be surprised at how often this is not the case and the buyer is actually dissatisfied when expected to understand their own needs. Salespeople without integrity aside, this mentality is what leaves people open to exploitation. It gets complicated when a buyer doesn’t properly understand their own needs and it’s left up to the seller to act on behalf of both parties. Obviously, they won’t want to leave food on the table.
Similarly, the salesperson has their own responsibilities. Obviously, they exist to generate cash flow but they must ask themselves if their sales process adds any value to the customer. A good salesperson has a duty to ask the right questions and fully understand the needs of their prospects. If they don’t align properly with your needs, then it should be no surprise that they didn’t close the sale.
As a buyer, it’s important to note that meeting needs is only an obligation of sales if it encourages sales. If more sales are made by selling what the customer does not need, salespeople are obligated to let the customer buy. At the end of the day, it’s entirely up to the customer to determine what their need is, and one could define the agreement of a sale meeting their need by the fact that they completed the sale.