Salespeople need to be reliable. Do you follow through with the things you say you'll do? Are you organized? Do you pay attention to detail? Are you knowledgeable about your product, industry, and customer's biggest business challenges? Early in the selling process, customers are concerned about whether or not you'll do what you say you will. If you successfully follow through, then your success will grow in other areas, as well.
– Contributed by Jeff Costello