That is a perfect mindset to address everyone you meet. Everyone has the potential to be your future customer. When you meet people with that mindset your interactions will be far different then meeting someone with whom you expect no future interaction.
Robert Thurman, the noted Buddhist philosopher contends what we as individuals will have unlimited interactions with each other and should treat every introduction and interaction as one in a long line of interactions.
Clearly we as human beings invest more energy if we believe we will have a ongoing relationship with the person we are interacting with. As entrepreneurs we must invest in ongoing relationships. Creating customer advocacy is about engaging future customers.
What have you done for your future customers today?