The most important lesson I have learned (and taught), is that you build relationships through integrity. This obviously works in all aspects of life, not just sales, but it is key to longevity in a sales environment and has been the backbone of my many sales endeavors throughout my career. If we (my customers and I) are going to mutually benefit from our working relationship, I have to outwork the competition and fully appreciate and empathize with what my customer wants and needs. Relationships, in life and in the office, are a two-way street.