It sounds like you're not very familiar with the industry.
One of the reasons Google's advertising programs are so successful is that they are measurable. A site can compute return on investment and know that for every $X spent on Google ad clicks they are generating $Y in sales.
One of the reasons Google's advertising programs are so successful is that they are measurable. A site can compute return on investment and know that for every $X spent on Google ad clicks they are generating $Y in sales.