Once you see that an answer is not serving its question properly anymore, it should be tossed away. It's just their natural life cycle.
They usually kick and scream, raising one hell of a ruckus when we ask them to leave. Especially when they have been with us for a long time.
You see, too many actions have been based on those answers. Too much work and energy invested on them. They feel so important, so full of themselves. They will answer to no one. Not even to their initial question!
The hardest thing about customer interviews is knowing where to dig. An effective interview is more like a friendly interrogation. We don’t want to learn what customers think about the product, or what they like or dislike — we want to know what happened and how they chose... To get those answers we can’t just ask surface questions, we have to keep digging back behind the answers to find out what really happened.
And what is delight? For me, delight is born from a tool’s intuitiveness. Things just working without much thought or fiddling. Delight is a simple menu system you almost never have to use. Delight is a well-balanced weight on the shoulder, in the hand. Delight is the just-right tension on the aperture ring between stops. Delight is a single battery lasting all day. Delight is being able to knock out a 10,000 iso image and know it'll be usable. Delight is extracting gorgeous details from the cloak of shadows. Delight is firing off a number of shots without having to wait for the buffer to catch up. Delight is constraints, joyfully embraced.