From their book Getting Real (emphasis mine)
Too many apps start with a program-first mentality. That's a bad idea. Programming is the heaviest component of building an app, meaning it's the most expensive and hardest to change. Instead, start by designing first.
Design is relatively light. A paper sketch is cheap and easy to change. html designs are still relatively simple to modify (or throw out). That's not true of programming. Designing first keeps you flexible. Programming first fences you in and sets you up for additional costs.
Another reason to design first is that the interface is your product. What people see is what you're selling. If you just slap an interface on at the end, the gaps will show.
A breath of fresh air!
Too many online retailers lack agility in their IT, despite having great smart committed developers.
Why is that?
How much blame should be placed on their development methodology?