"Timing" is the punchline for the joke on the definition of good comedian. "Timing" also separates a successful product concept from a poor product concept, even if the product is identical.
I had been a firm believer that asking the three questions and coming up with the "aha" factor lead the way to product success. Yet how many times have we heard "Great product, but way before it's time" ? Lately I've been working with an Entrepreneur in Residence with a VC firm. As we were grinding through a product definition he asked me:
" What is going on in the market which makes this right for today? What is different than 3 years ago? What will be different than 3 years from now?"
My head hurt trying to envision the entire market today, 3 years ago and 3 years from now. But we did in the product context and came up with the answer. And that is the final piece when evaluating a new product. You need to add "when?" to "so what, who cares, and what's the "aha" factor?"