My way [ie. the customers] or the highway! If you don't start with the customer / potential customer in mind what ever you measure is going to mean nothing, as you will have started from the wrong place.
When I say customer, I also mean target group of customers/consumers, this depends on whether we are talking B2C or B2B.
Whether you are creating a new product, or website, thinking about changes in price, redefining your media mix, or deciding whether to use new channels to market, it should all start with a very good understanding of the customer/target audience.
It is necessary to use both qualitative and quantitative methods to analyze the current situation with your customers, create scenarios from trends and come up with insights that help you drive your strategy and decision making. The subject of research methods is too long a subject to discuss here and there are many other blogs that do a great job of that.
There are so many diagrams and graphs searchable in Google when you search "customer centricity", like the diagram from Wisper, it explains how companies need to focus on the customer and how you internally lead the customer through the purchase funnel, but it flawed because it is from the company's perspective not from the customer's perspective. In fact non of the diagrams I found about customer centricity discussed it from the customer's point of view.
A consumer whether purchasing something for themselves or for their company, will go different stages in the purchase decision, I have mapped this out with the use of a rough mind map. This is by no means complete and may look different for different types of people/purchases/industries, but the important thing to bare in mind, is that people are not going to make decisions the way companies want them to, so get to know your customers, how they make decisions, who they turn to, how they turn to others, their time lines, when they need help with making their decision and at what stages they need help and ultimately when you can influence their decision.
In this diagram below, you will see multiple mentions of peer recommendations and zero mention of advertising, this is not to say that advertising does not play a subconscious role in their decision making, but they probably won't realize it is part of their decision, unless in fact their only decision is based on if it is from a particular brand, in which case they are a real fan of the brand [which is the aim of any brand of course]. More and more customers are turning to peers for advice during purchase in fact in recent surveys up to 78% trust peers compared with 14% who trust advertising. If brands use social media to build trust and not as an advertising channel, social media tools could also be considered peer recommendations.
The highway is a lonely place to be, so make sure you are being customer centric and go the customer's way. Customer is the 1st of the 6 c's of measurable marketing: customer, content, conversation, creation, convenience and conversion.