June 2005 issue of Harvard Business Review

reporting on the effectiveness of 500 various consumer and B2B marketing programs:
84% resulted in less market share, not more
Most customer acquisition efforts did not break even
Fewer than 10% of new products succeeded
Most sales promotions were unprofitable
Advertising ROI was below 4%
Doubling advertising expenditures for established products increased sales just 1% - 2%

However use Shopper's Voice and your world turns up-side-down!