answer:Your sale is not clearly understood by your customers. Say for example, that you sold toothbrushes. In that case, whoever you called on has a toothbrush, understands the need for the toothbrush, and all you have to do is sell them on why your toothbrush is better tahn their current one and they should buy it. In this case, the customer usually has little understanding of the medium your advertising appears in, distrusts its value, dislikes their own ignorance, is not convinced they need your service, is not convinced it will really work or what its benefit is. That makes your sale much harder. My suggestion would be to offer the person a way to measure the results in a short period of time in some concrete way. That decreases the risk for them.