Interaction Elasticity

Jakob Nielsen defines interaction elasticity:

Usability problems are like a barrier between you and your potential customers: the worse the design, the higher the barrier. Will users jump the hurdle? Some will, some won't. The lower your barrier and the more compelling your offer, the lower your interaction elasticity will be, and the more people will jump.

There are two strategies for increasing your website's business value: (1) do something that people really want and thus make demand less elastic, and (2) reduce interaction costs by increasing usability. I would do both.