I haven't worked in online advertising for a long time now, but when I did it was in the early days of retargeting, and the startup I was at was pivoting to doing search retargeting. But honestly, without any real metrics to justify it -- I suspect just investor interest / industry buzz.

I ran some quick numbers myself to see how the early experiments with it were doing, in regards to click through rates, and I didn't see any statistically significant improvements. I became very very skeptical -- one of the many things that led to me having a large fallout with the founder.

Now I'm sure in the intervening decade there's been improvements, and this is just one anecdotal datapoint, so I can't make strong claims about the efficacy of retargeting generally -- but I remain skeptical.

Go into the market for a mildly big ticket item other than a house and do some searches or browse some websites with privacy blockers off. You'll get start getting "relevant" ads.

I went to a e-bike manufacturer's website a couple months ago and they chased me around the internet with ads for like a week.

For me, this more often presents as ubiquitous ads for something I have already bought.

For some ads, i think google, you can click/tap on that blue little X to close it. Then a clickable field appears, and when you click, or tap on you can choose "I already bought this" among the reasons for why you closed that ad.

Question is if one is willing to do that, or not. I prefer blocking them.

Even more so on amazon

"yes Amazon I have just brought that TTRPG supplement why would I want to buy it again"

I once googled airport tow tractors to see what their specs were. Saw ads of airport equipment for months after... I'm nowhere near buying a 16-ton tug to move airliners around.

That would make for an awesome "saw a coupon, this is what they shipped!" story. Probably good resale to an FBO.

I'm in the market for a bigger house. Schibsted knows. Google still seems to have no idea.

I love it when they spam you with big ticket purchase ads right after you have made a purchase.

Yeah I'm full up on computers/cars/kayaks/trailers/riding lawnmowers right now, thanks.

Maybe sell me monitors or printers instead, or wait a month and show me fancy kayak paddles, GoPro, or roof rack mounts that save my back.

Generally I think the reason for you and others is that what you are interested in isn't advertising in their channel so it is always irrelevant.

I think the base cause of this is that we look for products based on life events; if the light burns out, we search for a new lightbulb. Google can't have this data (thank Dog), so can only serve targeted ads based on recent internet activity. Thinking of this in terms of PID loops, there's too much external interference, and too much lag in the loop for it to be really effective in calculating the next derivative.