Return on Investment for Usable User-Interface Design: Examples and Statistics (Aaron Marcus) -- "Making computer-based products (and services)more usable is smart business. Usability increases customer satisfaction and productivity, leads to customer trust and loyalty, and inevitably results in tangible cost savings and profitability. Because user-interface (UI) development is part of a product's development cost anyway, it pays to do it right." (Comments: PDF format! Thanks Gabriel White.)