Adaptive Path collaborates on a research project that aims to answer the questions How do companies currently use valuation methods, like return on investment (ROI), to measure the value of user experience? and What are the benefits of doing so? Here’s an excerpt from the executive summary PDF:
Our research revealed that using ROI and other valuation methods helps to evolve design competency within organizations. The valuation methods provide tools for developing and measuring a design strategy as a component of a larger business strategy: The ability to value user experience design makes it a visible and credible business lever on par with marketing, research and development, and channel strategy. As a result, applying ROI-measuring techniques to user experience investment decisions has a positive impact on how Web teams are structured and perceived within an organization.
Btw, Jason will be a guest speaker at AP’s User Experience Week in D.C. (August 16-19).
ROI can definitely support site design midifications but not always how the purists would prefer. For example, even though putting submit buttons at the top and bottom of a form may not conform to most UI guidance, if doing so increases success rates, it's worth doing.
Even though a lot of designers complain that they're not valued enough by business, I think very few are willing to put in the time or effort necessary to gain an understanding of how design can impact business.
This is why the people driving the use of design as a tool to gain a business advantage are enlightened business people (e.g. Steve Jobs, Bob Lutz, former VW head Ferdinand Piech, etc.), NOT informed designers.