Ask HN: I bought Voltaren at the chemist, now Google shows me ads for it. Why? • Hacker News Board

Re: Ask HN: I bought Voltaren at the chemist, now Google shows me ads for it. Why?

#41

Post by DavideNL » Sun, Apr 18, 2021, 11:07 AM UTC

Ovah wrote: post #23

Tangential: a while back I bought a very specific cheese from Lidl. And the very same evening I got a Lidl ad for that very cheese on Facebook. I have never signed up as a member, the only things that connect me to that place would be my credit card. I did bring my Android phone that has got Messenger lite installed, but that's stretching it tbh.

Your public ip provided by mobile/celltowers already reveals your location quite accurately (even with all location services turned off.) So it's definitely possible.

Google is an ad company, they sell your profile/interests and such to advertisers, it's their core business. So it's not "stretching" at all...

Re: Ask HN: I bought Voltaren at the chemist, now Google shows me ads for it. Why?

#42

Post by gonzo41 » Sun, Apr 18, 2021, 11:08 AM UTC

I guess it could just be coincidence?

Have you ever noticed how you don't seem to see much of X, and then all of a sudden you see one X. And then you can't stop seeing X.

Though, googles probably spying on you.

Re: Ask HN: I bought Voltaren at the chemist, now Google shows me ads for it. Why?

#43

Post by goatinaboat » Sun, Apr 18, 2021, 11:08 AM UTC

StavrosK wrote: post #19

halotrope wrote: post #9

It might be that you are just noticing the ads now that you bought the product. I read about similar observations recently. Might be a cousin of frequency illusion https://en.wikipedia.org/wiki/Frequency_illusion?wprov=sfti1

It's been a few times now where I've talked with my wife about some new product (physically, in the room) and she starts seeing ads about it. I thought that was the explanation too, but it's happened too many times for comfort. I know my devices are (probably) not listening, but I can't explain it either. Neither of us searched for the product or saw it online or anything, we just discussed something and got ads abou…

I know my devices are (probably) not listening, but I can't explain it either. Neither of us searched for the product or saw it online or anything, we just discussed something and got ads about it a few minutes to hours later.

It's probably statistical to a certain extent: people of your specific demographic are interested in a certain thing, and you are talking about it the same as all of your peers are, and a statistically significant amount of your peers did Google for it such that now Google assumes that anyone in your demographic will be interested.

Of course that only metas the problem up one level, which is that Google knows enough about you to do this kind of analysis a) on your cohort and b) on you.

Re: Ask HN: I bought Voltaren at the chemist, now Google shows me ads for it. Why?

#44

Post by 0898 » Sun, Apr 18, 2021, 11:09 AM UTC

jedwhite wrote: post #18

It's credit card purchasing data, which is sold and cross linked to your identity for advertising re-targeting. It is deeply invasive and should be blocked. It works like this. You go to a store and buy, say, a sexual wellness product. You then get targeted with ads online (search result ads, facebook ads, news media ads, amazon sponsored results etc) for the same product, or something related (let's say something em…

How would the card merchant know what specific product you bought though? Is that data transmitted too somehow?

Re: Ask HN: I bought Voltaren at the chemist, now Google shows me ads for it. Why?

#45

Post by tluyben2 » Sun, Apr 18, 2021, 11:10 AM UTC

This happens a lot and what I find the strangest thing is that the ads are for things I just bought: travel I just booked, freezer I just bought etc. I do not need anything again that I just bought and so these ads are even of less use than they normally are...

Re: Ask HN: I bought Voltaren at the chemist, now Google shows me ads for it. Why?

#46

Post by dorkwood » Sun, Apr 18, 2021, 11:11 AM UTC

rahilb wrote: post #30

It’s probably a coincidence or just the worst advertisers on the planet. Why would I show an ad to someone who literally just bought my thing?

It's pretty common. I once bought a fan online and had ads for that same fan follow me around for weeks. I believe they're called "retargeting" ads.

Re: Ask HN: I bought Voltaren at the chemist, now Google shows me ads for it. Why?

#47

Post by ancarda » Sun, Apr 18, 2021, 11:11 AM UTC

baybal2 wrote: post #29

Opt out of VISA marketing https://marketingreportoptout.visa.com/OPTOUT/request.do Second, disable GPS, and cellphone tower ID reporting (root needed.) So Google can't correlate you with sales records. At the moment, there is no way to disable Google AGPS spying on the stock Android. Third, block Google apps from reading your IMEI/IMSI/serial number, so they can't get AGPS data from your cellphone provider if it sell…

>VISA marketing

Why is this even a thing? Maybe I should just go back to buying everything with cash, it's impossible to keep up with all the crap we need to disable or hack around

Re: Ask HN: I bought Voltaren at the chemist, now Google shows me ads for it. Why?

#48

Post by jedwhite » Sun, Apr 18, 2021, 11:12 AM UTC

0898 wrote: post #44

jedwhite wrote: post #18

It's credit card purchasing data, which is sold and cross linked to your identity for advertising re-targeting. It is deeply invasive and should be blocked. It works like this. You go to a store and buy, say, a sexual wellness product. You then get targeted with ads online (search result ads, facebook ads, news media ads, amazon sponsored results etc) for the same product, or something related (let's say something em…

How would the card merchant know what specific product you bought though? Is that data transmitted too somehow?

Yes, the product details are included.

Re: Ask HN: I bought Voltaren at the chemist, now Google shows me ads for it. Why?

#49

Post by murukesh_s » Sun, Apr 18, 2021, 11:12 AM UTC

baybal2 wrote: post #29

Opt out of VISA marketing https://marketingreportoptout.visa.com/OPTOUT/request.do Second, disable GPS, and cellphone tower ID reporting (root needed.) So Google can't correlate you with sales records. At the moment, there is no way to disable Google AGPS spying on the stock Android. Third, block Google apps from reading your IMEI/IMSI/serial number, so they can't get AGPS data from your cellphone provider if it sell…

Also google may read your email (if you are using gmail) - which contains your bank receipt (so seller), time and amount.

Re: Ask HN: I bought Voltaren at the chemist, now Google shows me ads for it. Why?

#50

Post by morelandjs » Sun, Apr 18, 2021, 11:13 AM UTC

I’m going to guess that the drug store sold your transaction information. Who they sell it to varies from chain to chain, but it’s common practice. For example, CVS in the states sells your purchase data.

If you want to avoid being tracked, use cash.