While pivoting may still be all the rage, how you start often defines how you will finish. That's true for Oprah, who starts every meeting with the same three sentences. That's true for Jeff Bezos, who asks himself one question before making every important decision.

And that's definitely true for how Amazon, as John Rossman, the former director of enterprise services at Amazon, writes in Think Like Amazon: 50 1/2 Ways to Become a Digital Leader

Before Amazon starts any project, it first determines exactly how it will measure the customer's response to the outcome. 

One example: When Rossman was launching Amazon Marketplace, the business unit that today accounts for over 50 percent of Amazon's total sales (but at the time was viewed outside the company as a huge gamble; why would any company intentionally bring competition in-house?), here's what Rossman pledged the initiative would deliver:

A third-party seller, in the middle of the night without talking to anyone, would be able to register, list an item, fulfill an order, and delight a customer as though Amazon the retailer had received the order.

(According to Rossman), This simple sentence imposed a tremendous amount of integration and operations coordination between Amazon Marketplace and our sellers.

That meant measuring, in real time, the ease, speed, and reliability of the seller sign-up process. The ability for sellers to list individual products. Amazon's ability to meet the same fulfillment standards for third-party orders as its own orders.

In short, for customers to feel like every order on the Amazon site felt like every other order -- regardless of the seller.

Do that -- achieve that -- and Amazon Marketplace could become an important part of Amazon's flywheel, the self-reinforcing loop where initiatives feed and are in turn driven by each other.

As Brad Stone describes an early version of Amazon's flywheel in his book, The Everything Store:

... Bezos and his lieutenants sketched their own virtuous cycle, which they believed powered their business.

It went something like this: Lower prices led to more customer visits. More customers increased the volume of sales and attracted more commission-paying third-party sellers to the site. That allowed Amazon to get more out of fixed costs like the fulfillment centers and the servers needed to run the website. This greater efficiency then enabled it to lower prices further.

Feed any part of this flywheel, they reasoned, and it should accelerate the loop.

But the loop would only accelerate if Amazon delivered what Rossman calls "customer value." 

Which is why Amazon sometimes spends as much time developing the right metrics as it does developing ideas and project plans. No idea, no matter how "groundbreaking," is a good idea unless it actually works in an objective and measurable way for the people for whom it is intended to work.

That's why Amazon never starts a project until it determines exactly how it will measure customer response.

And neither should you.

If you're hiring a marketing director, you're not just filling a position -- you're hiring a doer of important things that need to get done. Since every employee you hire is an investment; determine ahead of time the return on that investment you expect, and how you will track the results. See yourself as the customer -- and make sure the outcome delights you.

The same is true for deciding whether or not to introduce a new product or service. Don't just calculate potential financial return; determine how you will measure customer response. Financial metrics are important, but customer metrics are just as important: A project that only breaks even financially may result in a major improvement in customer loyalty and, in time, long-term customer value.

At first, Amazon Marketplace sales may have cannibalized Amazon's own sales... but in time, the exponential growth of third-party sellers and resulting products available has made Amazon responsible for nearly 50 percent of all U.S. online sales. 

The same is true for almost anything you might do. Say you want to get in better shape. First, define "better shape" in an objective and measurable way. Then determine exactly how you will measure success: Time, or distance, or pounds lost, or weight lifted, or blood sugar levels reduced... never start until you know exactly how you will define and measure the outcome.

The next time you think about starting something new, whether professional or personal, take a step back and determine how you will measure the results from the customer's point of view.

Even if -- maybe especially if -- you are the only customer involved.