When a customer makes a mistake and a company has no obligation to help, it's a great chance for the company to get a customer for life--or to lose one. Let me explain how Priceline (PCLN) lost me as a customer and Apple (AAPL) got me to be customer for life.

I recently arrived at an airport for a wedding with a toddler who doesn't travel easily, got to the Budget desk and learned that my Priceline reservation didn't exist--and there were no more cars available at the entire airport. It turns out it seems it was my mistake: somehow I booked the $370 reservation for a prior week. I contacted them to explain the situation and the Philippines-based customer service woman politely read her script telling me they don't care, and that I lost all the money. Priceline similarly lectured me via Twitter after I contacted them that way too.

It took us two hours and hundreds of dollars to get a rental car a long way from the airport--and my toddler was not happy, as any parent can imagine.

Contrast this to what happened when I spilled water on my MacBook Pro a few years ago, voiding the warranty. I took the dead computer to the Genius Bar and the technician explained how the repair would be well over one thousand dollars--but despite having voided the warranty, Apple would repair the computer for no cost to me.

I have since bought several MacBook Air notebooks; four iPhones; three iPads; and thousands of dollars of content from Apple. I'm an Apple customer for life.

In both cases I, the customer, made a mistake. One company choose to value $370 over my loyalty; another chose to spend over $1,000 to prove their loyalty to me as a customer.

My suggestion is to not lecture an unfortunate customer about rules but rather take the opportunity to prove how much you value their business. And I suggest you buy Apple and avoid Priceline.