Businesses don't want to pay for marketing that doesn't work and the simple answer is targeted ads work. Advertising to anyone that reads the New York Times, when a business can target people that are searching for a couple of key words relevant to the business' product? Even if it's the company's money and not my own, I'd rather spend it on something with a provable ROI, not just blindly blowing money showing ads to people that wouldn't or can't buy the product.