"Work" is loosely correlated with "Make money out of it" (especially for the ad seller) The buyer of ads does (usually) keep track of conversion (as correctly

"Work" is loosely correlated with "Make money out of it" (especially for the ad seller) The buyer of ads does (usually) keep track of conversion (as correctly pointed in the article, also the seller) and when optimizing their strategy they're usually ok with the results they get from it (because they sell and they have sales attributable to the online ads) But here's the catch, making a more efficient ad probably doesn't make the sellers more money.