Unlike most companies, T-mobile USA does not present their "mission statement" in a very formal, business way to their customers. No special "mission statement" link, no "Our Mission Statement" heading, nor is it set apart from the rest of the history of the company. Instead, they present their "mission statement" in a very informal, customer-friendly manner, stating how the reason why they ARE in business is FOR the customer:
"The value of our plans, the breadth of our coverage, the reliability of our network, and the quality of our service are meant to do one thing: help you stick together with the people who make your life come alive. That’s why we’re here." - T-Mobile USA (follow link to the quoted page)
T-mobile USA makes providing services, plans, and a reliable network to their customers, increasing their customers' connectivity in a relatively disconnected world, their "mission statement."