One of the most useful design practices I have found is prototyping. It helps to have a solid model that everyone can relate to as the design and development progress. I recently learned of a company that use prototyping in an area where I would not have considered it possible - marketing. Apparently they test marketing approaches to tune the marketing strategies of their clients. I guess that just goes to show how valuable and broadly applicable the practice of prototyping is.

I just had a thought about design - a designer understands that one size does not fit all - a marketer works on the assumption that one size can be made to fit all - or at least a sizable population.

Marketing of products and services is influential because money is best made through volume. This is detrimental to the design process of making sure that those products and services are working for people because it is often easier and quicker in the short-term to teach people to work with the limitations and biases of the technology being sold.