In going through some old stuff in my Outlook, I found this from Good Experience--You DO Talk to Customers, Don't You? :
"By definition, any customer experience project must involve real, live, actual customers. It's not adequate to operate solely from pre-defined rules, reams of quantitative data, or hypothetical (and fictional) stories of users. Customers themselves must be the focus of the research, and their experience on the site must be the basis of the resulting strategy."