Not all prospective buyers you come in contact with are going to be those you want to spend time and energy on cultivating. No matter what business you are in, there will always be buyers who provide greater value to you than others.
So, you must be able to differentiate between those that are profitable for you and those that are not, those that are costing you more money or time than they are worth. How?
By calculating your buyers lifetime value. Simply determine what it costs you to attract and retain a given buyer, then subtract the revenue that partnership may bring to your business. Many may seem profitable on the surface and end up providing a negative return on your investment. Then comes the hard part. You need to get rid of or walk away from those costing you too much time, money and/or effort.
Once you have done this you will be better able to target your sales efforts to focus on those you want to do business with, who will most likely help you and your business to grow.
Food for thought.