I don't know if this is the right place to ask this question, but I would like to give it a try.

A couple of days ago I was looking for a product that I wanted to buy. Visited a couple of websites, webshops, used some keywords in Google. Didn't buy anything.

The day after, I received a welcome email from a website I've never visited (I am 100% sure I never did). It's a website that offers products on discount. Thought it was a bit weird, it even had my name in it, and I wondered: why am I subscribed to this list.

But when I opened it (just curious), it became scary: the product I was looking for the other day was mentioned in it! They gave me a coupon so that I could buy the product for almost nothing.

Usually I am not that paranoid and of course it is not a big problem, but I just don't understand how this works. Is this even possible? How does this kind of marketing (?) work? Like I said I am 100% sure I never visited the website.

Hope someone can help me out (and sorry if I am posting this on the wrong page).

2 Answers 2


Welcome to the age of online services which you think are there to help you find what you want on the Internet, but are really there to mine your personal information and online activities in order to sell and generate advertising revenue.

It is not coincidence that when you carry out searches for a certain item, afterwards many sites you visit will have ads for that item. When others view those same sites, they don't get the same ads -- they get ads relevant to their online activities.

This is worth a read: https://www.google.com/policies/privacy/

This is only one service and it's privacy policy. Look at all the services you use and their privacy policies. You can't avoid this type of data mining just by switching browsers. Even without logging in, your searching activity is still used to mine and correlate your IP address and other data points that help to identify you on your PC.


There are a few ways this could be done. Did you happen to be logged in to your google account while surfing these websites? If so, the fact that you used Google to search anything could have been the cause. Google uses your search criteria and even content of your emails to advertise to you, sometimes through 3rd pat affiliates that will send you emails .

Regardless, two things are for sure, this website is somehow affiliated with one of the sites you used and they've successfully acquired your information and search criteria to advertise to you. This is the result of using free email services that nearly everyone uses these days. Nothing is ever free online, you always pay for it somehow.

  • Not sure Google would give third party information like that?
    – Anders
    Oct 2, 2017 at 13:06
  • I am not sure, but I believe I wasn’t logged in. Is what happened possible if I never visited this particular website?
    – V. Hollan
    Oct 2, 2017 at 13:19
  • Google have one of the most comprehensive personal data collection facility, but Google would never send your email and search data (personally identifiable data) like that to third party as that'd be disastrous to their business model. Google's primary business model is to generate relevant ads, and their model is designed such that they keep all your personal data to themselves so sites and advertisers cannot run away with your details to advertise directly to you.
    – Lie Ryan
    Oct 2, 2017 at 16:43
  • you are correct my wording was poor in my explanation and I've removed that part. Google sells ad space, then take your email tags and search history and plug your information in to those ads for the third party affiliates for the most part.
    – cclater
    Oct 2, 2017 at 17:48

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .