I think marketing departments know something they will not acknowledge: they do not know how marketing works.
For example: I bought a pair of glasses from Warby Parker. Well, it was my second pair and the first pair I bought online. Immediately, I saw ads for Warby Parker on Google as well as on Facebook (how? IP address?). It bothered me because I had just bought a pair and more importantly, I didn't want them to waste money chasing me. I found it especially troubling because they claimed to be doing social good by donating a pair of glasses which made me think every dollar they spend on badly targeted ads is a dollar not going for a good cause. Also, because I saw the same ad everywhere I assume it means they outbid the competition handsomely?
I don't know what I am trying to say. I have to think about it. Am I for better targetted ads?