Put customers first and everything else follows

W Edwards Deming said something like:

The real purpose of a company is not to make money, but to create customers who are so pleased that they will continue to buy products.

Don’t fixate on sales figures and profits. Get your relationship right with your customers and end-users and everything will follow. Work from the outside, in. Continuously collaborate with your customers and end-users. See everything from their point of view first. Understand value from their perspective. Have your efforts be driven by your customers and end-users. Ask them what they want next and let their requests pull you ahead of the competition.

ahammad:
This is very basic, I see many cases of failures to serve customers well, whatever the customer is a colleage or external to the organization, the same principles should apply.