> You can use web analytics to measure a conversion rate from ads. Hence user clicks ad -> sales happens (in the best cases). That's Internet Ads 101.
As the article pointed out though, the ad conversion rate is so low, it is very difficult to separate the signal from the noise, particularly for smaller campaigns. There is also the additional issue that the ad itself doesn't necessarily directly lead to a simple click->convert cycle. Having worked in the industry for the better part of the decade, I can tell you that separating the signal from all the noise absolutely does require a ton of data. There's a reason why "Big Data" rose to prominence in the advertising world.
As the article pointed out though, the ad conversion rate is so low, it is very difficult to separate the signal from the noise, particularly for smaller campaigns. There is also the additional issue that the ad itself doesn't necessarily directly lead to a simple click->convert cycle. Having worked in the industry for the better part of the decade, I can tell you that separating the signal from all the noise absolutely does require a ton of data. There's a reason why "Big Data" rose to prominence in the advertising world.