Comment by dan-robertson

A problem is that deciding whether or not a customer was converted from an ad viewer is done by the people you pay for ads. Perhaps the conversion numbers are slightly inflated but in general it’s just really hard to tell. If you show a lot of ads to potential customers then chances are, most people who buy things from you saw your ads. Does that mean they came to you because of the ad? I think even if you had perfect information it would be hard to decide. There is some chance that you just have an added sales tax where you send $6 to each advertiser every time you make a sale. I don’t know how much (eg) google care about deciding whether conversion numbers are correct. But how do they even decide if the numbers are correct and what stops them from being biased towards reporting higher conversion rates?