Test Driven DesignTM

What is the difference between Test Driven DesignTM and marketing research?

An example is the best way to understand and compare. If marketing research were… a truck, it would deliver a large number of packages but it would take time to load and unload them, it would need a special driver’s licence and all this would be expensive. If Test Driven DesignTM were… a van, it would deliver the right quantities regularly, fast, at a lower cost and just in time according to the current needs. Even if sometimes it’s necessary to do marketing research, usually Test Driven DesignTM responds to the immediate needs and allows developing an efficient concept right away.