Apropos of the current discussion about dropping Google advertising [1], I'd appreciate HN's thoughts on how a very particular product was targeted at me yesterday: a semi-obscure muscial instrument (which I won't name, my paranoia is already piqued).
Yesterday morning at home I Googled the instrument, the name of which I didn't actually know but Google came to the rescue. I browsed Google Shopping [2] but didn't purchase one.
Later I went into work where Facebook displayed an ad for the instrument in its "sponsored" section and an inline "suggested post" for a manufacturer.
My home and work computers and networks are completely different. I typically use incognito mode and "do not track" in Firefox or Chrome. I sign out of all social media and Gmail. Yesterday I was working in a large building with tens of people all using wifi used by hundreds of people across several buildings.
I assume no outright nefarious activity, such as an illicit pipe of potential customer IDs between Fb and Google.
The best I can theorise is that I had an open Fb window at home, and one of the instrument manufacturers' websites had an embedded Facebook like button or similar tracker, and they are running targeted ads on Fb. But is this direct-to-an-individual targetting even possible on Fb? Perhaps the obscurity of the instrument meant that I was very likely to see an ad, and very likely to notice it.
I typically close Fb when I'm not using it, so this doesn't immediately feel like what happened. I'll be doubly-sure to close and log-out Fb now.
I can't think of other ways that my Google activity could get to Fb. Browser fingerprinting, cellphone location etc would allow Fb to understand my location, but I can't see how they'd match this against Google activity.
I'd be very interested to read how this is, or could be, achieved.
[1] https://news.ycombinator.com/item?id=14094083
[2] https://www.google.com/shopping
If you have ever signed into FB from home, they know that machine / ip / whatever fingerprint is you. Even after you sign out, its still out. Even if you are in ingocnito mode, its still probably you. Then you sign in to FB at work, and now the same thing happens. They may not know the specific computer, but they know the network you are connected to IP wise.
This happens across many different ad networks, and they are all connected to sell ads targeting the people something wants. If you leave a potential purchase not bough, and sometimes even when you do buy it, ads are going to make it back to 'you'. They may not know 100% that it is you, but they can cast a net to try and find you. And for something like a missed sale, its worth the cost.
Note it may not be targeting you specifically. It may just be closer to: Someone in this VERY specific demographic looked for this instrument, oh hey here is someone else that meets that same demographic on this other ad network. Lets try them.
The amount of tracking on the internet nowadays is absolutely crazy. Visit practically any website, and all the major players are going to know about it and add it to their profile of you.