Wondering why I say target CPA and target ROAS should be monitored and managed rather than left alone? We should because there are factors in everyone's business that Industry Email List affect conversion rates that Google's prediction systems may not take into account. Automation only detects a change in metrics and, in its narrow scope of what it can do, may very well use that data to do the completely wrong thing for the business. Here's an Industry Email List example that I've personally encountered... One day, automated bidding noticed that conversion rates had dropped significantly,

So bids were lowered in order to maintain the target CPA. Due to the much lower bids, the advertiser's conversion volume Industry Email List skyrocketed and never Industry Email List automatically recovered. Here is what happened. Auction automation correctly saw a drop in conversion rate and lower adjusted bids. But as a dumb automation, it never asked why the conversion rate dropped. The humans knew it was because a new landing page had launched. Humans would have known that the correct response to this event was to return to the previous landing page rather than to lower the bid.

Machine learning is bad, very bad at explaining Industry Email List why and how. Show him a picture of a cat and he knows it's a cat. But good luck getting him to explain why it's a cat. In my book on the future of digital marketing, I explain that one of the roles humans should play is that of a PPC driver, someone who monitors automations and can make course Industry Email List corrections if bad data leads bad deeds. Understand what the machine does and make sense of the data it uses to make its decisions. That's pretty much what Hal Varian said in the quote I mentioned earlier.