> Their advertising sends people to dedicated landing pages where they can be tracked through the site and measured if they convert. But how much of this is se

> Their advertising sends people to dedicated landing pages where they can be tracked through the site and measured if they convert. But how much of this is selection bias and how much of it is really having an impact? This reminds me of https://thecorrespondent.com/100/the-new-dot-com-bubble-is-here-its-called-online-advertising/13228924500-22d5fd24 https://thecorrespondent.com/100/the-new-dot-com-bubble-is-h... >Economists at Facebook conducted 15 experiments that showed the enormous impact of selection effects. A large retailer launched a Facebook campaign. Initially it was assumed that the retailer’s ad would only have to be shown 1,490 times before one person actually bought something. But the experiment revealed that many of those people would have shopped there anyway; only one in 14,300 found the webshop because of the ad. In other words, the selection effects were almost 10 times stronger than the advertising effect alone! Sure you can measure clicks and how many convert, but that does not necessarily measure the effect of the ad. I think most of the time the true effect of an advertisement is usually unknown (what is the difference in outcome of using the ad vs not using the ad?) and I suspect that in a large number of cases the impact of advertising is significantly overestimated. Perhaps people won't find out until they are forced to cut back on ad spending then they might realize that it isn't as important as they thought. https://freakonomics.com/podcast/advertising-part-2/ https://freakonomics.com/podcast/advertising-part-2/