"Don't make your problem the customer's problem!"
There are often many technical solutions to create a particular customer experience. Jeff never accepts false dichotomies. If the particular technical solution being considered fails to produce a delightful customer experience then you better start thinking about other solutions. Many of the projects on which I worked turned out much better when Jeff challenged us break out of our little technical boxes and consider alternate solutions that preserved the customer experience.
I can sense that my answer will be frustrating to some who don't like being told that they aren't thinking big enough / creatively enough / bold enough / outside the box enough. Believe me, I felt that way too when working on Jeff projects. I left his office in frustration many times only to realize several hours or days later that I would have been better served by focusing on creative problem solving instead of trying to convince Jeff that X was not possible.
I have immense respect for Jeff. I also have increased respect for Sergy because he appears to be asking the right types of questions at Google.