The blog by Whitney Hess was great. (Whats your problem putting purpose back into your projects)
The examples given are simple but powerful. When design requirements understanding and solution are done from the technologist’s point of view, the products do fail to take off. Even if they take off they may not remain leaders for long. The users perspective is important. While the tools are available and been used by marketers for long, in my view the ability think and act like use (at least visualize) is more important than the tool itself.
A classic example (my favorite) of failed product is Interactive Baby Feeding Bottle. Practically Speaking who would prefer such products. The joy of feeding baby or watching baby using Feeding Bottles cannot be substituted.