When you say something is a worldview, you are saying that that is how you view the world it is a special kind of perspective that affects how you look at issues and how you treat the people involved in those issues. Hence, when we talk about a Customer Centric worldview, we are saying we want to adopt a perspective (or mindset) which is focused on the needs and wants of the customer rather than our own needs and wants.
This sounds good in theory, but how does it apply in real life? A Customer Centric worldview is one where you (the sales person) go beyond simply treating the customer nicely and will extend to trying to see how your actions as a sales person affect the customer as well, particularly with regards to how he can buy a product or use a service.
The best way to understand a Customer Centric worldview, perhaps, is to contrast it with a Non-Customer-Centric worldview where a sales person simply thinks about his own thoughts, attitudes, needs and wants rather than that of the customer. A prime example of this are those sales people who take extended coffee breaks while on duty, prefer to gossip with fellow sales people even when customers are frantically looking around the sales area trying to find someone to assist them, and refuse to explain product attributes to customers because it would take up too much of their personal time, energy, and patience plus, heck, sales is just plain boring, right?
Some sales people really have an inborn Customer Centric worldview which is why such people make ideal sales people. But we also have sales people from hell who got into sales purely for the potential income they could make and really do not care what the customer winds up doing. For the latter kind, no amount of training would ever be enough to give them a Customer Centric worldview. Fortunately, such people usually do not last long in sales anyway.