NEW YORK (AdAge.com) -- "There has never been a time in the history of the United States when we've seen a destruction of credit on the magnitude we've had in the last twelve months," said Carl Steidtmann. The chief economist for consumer business at Deloitte Research was speaking at the National Retail Federation Convention last week. His message about the "de-leveraged consumer" and the future of marketing was not an upbeat one.