Great post that illustrates the benefits of marketing testing.
"The culture of experimentation at Amazon, where data trumps intuition, and a system that made running experiments easy, allowed Amazon to innovate quickly and effectively."
"Controlled experiments provide a methodology to reliably evaluate ideas ... Most organizations have many ideas, but the return-on-investment (ROI) for many may be unclear ... A live experiment goes a long way in providing guidance as to the value of the idea."
Testing gets at the heart of marketing because its one of the methods of listening to the customer, do they buy, do they not, do they buy more!