Even if you are working for a company and never see a single customer, are you not offering service within your task list to your own workplace, co-workers, and employer? By making each associate very aware that they have a higher purpose than just doing their task list (but instead delivering the best possible service within their task list), you create a sense of urgency in which every action that they do affects a customer. After you get into this mind-set, you can start under-promising and over-delivering on that service that you give, for every aspect within those assigned tasks.
When you lead by example and put this thought into your routine, there is a synergy that is produced; you realize that the value of the whole organization is dependent upon the service that you produce with everything you do and say. "Visualize great service-delivery first, all things possible thereafter."