Why Search Doesn't Really Matter
The purpose of advertising is to create demand for a product or service. Advertisers want get people to give them money. And they want to forge a lasting relationship with those people, so they can continue to get paid. Every dollar spent by an advertiser is an investment in the creation or maintenance of a financial relationship with a person.
If advertisers could know that every dollar spent would come back to them as a revenue-positive event, they would spend an almost infinite amount of money. That obviously isn't the case, as some types of advertising are more effective than others. And generally those effective forms of advertising are a scarce commodity.
