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Ask HN: How does Facebook know what I buy on Amazon or vice versa?

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Re: Ask HN: How does Facebook know what I buy on Amazon or vice versa?

#121

Post by dhimes »

theweirdone wrote: post #106

As others have pointed out, it's an advertising technique called retargeting. Here are some of the technical details of how exactly it is done(Facebook's implementation might differ somewhat from this, but overall concept is same) /* DSP - Demand side partner (Entity which works with someone who wants to show their ads) SSP - Supply side partner (Entity which works with some who have potential space on web to show ad…

It's weirder that that. I was notified via a Facebook ad that my Navionics subscription to charts from Asia expired. I only use Navionics as an ios App.

Re: Ask HN: How does Facebook know what I buy on Amazon or vice versa?

#122

Post by hakcermani »

darylfritz wrote: post #30
thisismine wrote: post #21

Earlier quoted context omitted.

Cookie is a thing.

OP also said they used two completely different browsers

From the same network ? If both browsers are from different computers (worse still from same computer) from same network then the externally visible ip address is the same isn't it ?

Re: Ask HN: How does Facebook know what I buy on Amazon or vice versa?

#123

Post by theweirdone »

oelmekki wrote: post #117
theweirdone wrote: post #106

As others have pointed out, it's an advertising technique called retargeting. Here are some of the technical details of how exactly it is done(Facebook's implementation might differ somewhat from this, but overall concept is same) /* DSP - Demand side partner (Entity which works with someone who wants to show their ads) SSP - Supply side partner (Entity which works with some who have potential space on web to show ad…

Thing is, OP mentions using two different browsers, which is why it's surprising. I guess there's still the possibility that a cookie was added months before that and that "tainted" browsing was forgotten. But it's still worth wondering if some other identification mechanism could be at play.

Or, facebook(https://www.facebook.com/business/learn/facebook-ads-reach-e...) matches this cookie to your fb account in their system. Then making this information available across the browsers is trivial.

Now, to actually think of implementation, I can't even imagine the amount of data they need to store(and clear in LRU manner) to make this work.

Re: Ask HN: How does Facebook know what I buy on Amazon or vice versa?

#125

Post by dtft »

reustle wrote: post #11
dtft wrote: post #7

Three words......Facebook Tracking Pixel You go to Amazon, they tell Facebook what you are looking at, and then can dynamically create ads specifically for you.

Does Amazon really use the fb tracking pixel? I wouldn't think so

Looks like they don't! Must be a different retargeting technique used by Amazon. FB Pixel could have also been on manufacturer's site.

Re: Ask HN: How does Facebook know what I buy on Amazon or vice versa?

#126

Post by saluki »

oelmekki wrote: post #117
theweirdone wrote: post #106

As others have pointed out, it's an advertising technique called retargeting. Here are some of the technical details of how exactly it is done(Facebook's implementation might differ somewhat from this, but overall concept is same) /* DSP - Demand side partner (Entity which works with someone who wants to show their ads) SSP - Supply side partner (Entity which works with some who have potential space on web to show ad…

Thing is, OP mentions using two different browsers, which is why it's surprising. I guess there's still the possibility that a cookie was added months before that and that "tainted" browsing was forgotten. But it's still worth wondering if some other identification mechanism could be at play.

I'm sure they are tracking/matching by cookies, ip, FB logins, geolocation, etc . . . by combining those it's pretty easy to serve up the right ad, most of the time.

Re: Ask HN: How does Facebook know what I buy on Amazon or vice versa?

#127

Post by muzuq »

a13n wrote: post #86
md224 wrote: post #44

Earlier quoted context omitted.

But... what about step 2? > Like a building full of PhD's advanced. On a more serious note, it's unfortunate that so many smart people use their intelligence to enable this kind of gross technology. It's all about "solving puzzles" rather than making the world a better place. There's gotta be more productive ways to advance your career.

> it's unfortunate that so many smart people use their intelligence to enable this kind of gross technology We live in a capitalist society. It just so happens that this "gross technology" makes advertising insanely profitable for millions of companies (mine included), which makes FB billions, so they'll happily pay really smart people millions to build it. And those smart people will happily accept millions to solve…

>We live in a capitalist society.

Always a solid cop-out for allowing bad things to continue

Re: Ask HN: How does Facebook know what I buy on Amazon or vice versa?

#128

Post by DonHopkins »

smcl wrote: post #78
hiisukun wrote: post #57

Earlier quoted context omitted.

I love picturing a room full of PhDs developing a crazy complicated algorithmic wonderland. Their celebrations at the complexity and genius of their work probably cut short, when users are targeted with ads telling them to buy something that they just bought. When human male user "Joe" purchases a women's bath robe 1 week before Mother's day, does he really need ads for women's bath robes for the next month? Of cours…

Courtesy of @kibblesmith on Twitter: Amazon is a $250 billion dollar company that reacts to you buying a vacuum by going THIS GUY LOVES BUYING VACUUMS HERE ARE SOME MORE VACUUMS https://twitter.com/kibblesmith/status/724817086309142529?la...

Nature abhors an empty vacuum.

Re: Ask HN: How does Facebook know what I buy on Amazon or vice versa?

#129

Post by eeZah7Ux »

kbart wrote: post #107
eeZah7Ux wrote: post #82

Earlier quoted context omitted.

You can't tell in advance what trains, in general, will carry. When writing ad targeting code, user surveillance, nuclear missile guidance, VW pollution test circumvention code... you know exactly what is going on.

Not necessarily. I don't know much details about other technologies you have mentioned, but user surveillance has many overlapping technologies with IT security: deep packet inspection, network flows monitoring, white/black listing etc. can be used for both good and evil and switched in-between quite easily. I'm very pro-privacy and sometimes get to work with such technologies, though I emphasize that what I do is st…

> deep packet inspection, network flows monitoring, white/black listing

This is usual network security.

At some point someone need to glue together existing devices and software into something that has an obvious use case with ethical implications e.g. the chinese "great firewall".

Re: Ask HN: How does Facebook know what I buy on Amazon or vice versa?

#130

Post by godot »

Aside from basic retargeting with cookies, there's definitely something more going on between Facebook and Google. (geoip/location might be a good guess)

I have a habit of going into Incognito browsing often. Not for viewing any NSFW stuff, I just have this habit whenever I want to look up something that I know is very one-off and not related to my general interests. (habit started with Amazon and it showing me related products of stuff I wasn't interested in because I clicked on a link friends send over skype)

A few days ago I was sitting at home, remembered about a specific couch-in-a-box company, wanted to check out how the couch looks again, so I opened up Incognito as I always do, and searched for Burrow.

Later on that night, I saw Burrow facebook ads. Not only was I in incognito when I searched, and this time I was actually on a whole different laptop while on Facebook!

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