I sat with my wife at my laptop and discussed whether to buy a particular coffee machine or office chair as I looked them up on Amazon UK (my account) and read reviews.<p>One hour later they showed up on Amazon ads on <i>her</i> Facebook account. Very dodgy.
I've noticed this phenomenon as well, but one thing you can do is watch the network traffic on your router, and you'll see that they aren't snooping in on your conversations. What's likely happening is that Facebook knows that you're married to her, and since spouses/friends/close relationships tend to have the same general interests, it's a good way to narrow down the scope of advertisements for you and your social graph. If you search for a coffee machine, then your wife is also likely to search for a coffee machine, therefore, it follows that Amazon would show an ad for a coffee machine to your local network.<p>Like I said, I've definitely observed this phenomenon before. I've also observed that it's likely confirmation bias: I don't remember all the OTHER things Facebook advertises to me. The only reason that ad for the coffee machine jumps out at me is because I was just talking about it, but who knows how many times it showed up on my feed and I just glossed over it because I tend to gloss over ads?<p>Posts like this come up quite often, and I definitely think it's dodgy and suspicious, but ultimately, I think it's just clever marketing tactics by Facebook to determine what to advertise to you.
It's not that crazy, they have several signals that they can use to make that determination. It's not black magic or anything "dodgy".<p>It's probably some combination of your IP, cookies, location, account relationships, credit cards, etc etc. There's a lot of pretty simple data they can use to make the decision to show her Ads on Facebook's Ad platform.
What happens if Amazon uses the lookalike audience feature of FB? He uses the contact details of customers who was looking up the coffee machine and automatically defines a group of FB users who look alike them. In this case your wife looks alike you. Or if I would have developed the lookalike audience feature I would say she looks alike you. That is why she gets ads for the coffee machine.<p>[edit:] This may be considered as dodgy. In Germany it is forbidden to use the lookalike audience feature of FB and companies are fined if they admit using it.
Below are the scenarios:<p>1. Amazon passed your [IP address + SKU browsed] to facebook ad platform. And facebook knows from there on.<p>2. Facebook snoops on your audio and its ad platform pulled SKU from amazon.<p>3. You have various extensions on your browser which can "read all websites data you visit" - which have sold your browse information with IP to facebook.<p>Third is most likely.<p>+ I have noticed - "somehow" my facebook learns what I watch in youtube and vice-versa. Only way this could happen is via one of my "trusted" browser extension!
Facebook tracks your browsing history even if you log out. I suspect Amazon is the same way. Does it bother you to know that these sites can track almost every site you visit? If not, why does it concern you that it can link your account to your wife's.<p>Clear all cookies between browser sessions.
I often search for things at home on my personal laptop only to see them on my facebook at work on a different location/machine.<p>I assume its due to the fact your amazon has been linked to her facebook account at one point or another as you were logged in to both at some point.
Meanwhile people don't hesitate to upload photos of their homes, kids, trips, places they go everyday, to some random FB and google servers.<p>I mean, we're talking basic product advertisement from the largest store in the world...
Same happens when your friends are looking for something, they are in your network so you might be interested to. Second, you share a house / ip addressess so easy to link those together.