" Direct marketers, of course, realize that measurement is the key to success. Figure out what works, and do it more! Mass marketers have always resisted this temptation. When my old company approached the head of one of the largest magazine publishers in the world and pitched a technology that would allow advertisers to track who saw their ads and responded to them, he was aghast. He realized that this sort of data could kill his business. He knew that his clients didn’t want the data because then their jobs would get a lot more complex. Measurement means admitting what’s broken so you can fix it. Mass-media advertising, whether it’s on TV or in print, is all about emotion and craft, not about fixing mistakes. One reason the Internet ad boomlet faded so fast is that it forced advertisers to measure – and to admit what was going wrong. "

― Seth Godin , Purple Cow: Transform Your Business by Being Remarkable