How is site tracking implemented?

Question

Fight against spam

Good evening. I recently looked at sites with motor oil, by the evening I had already forgotten about it, when this message came to VK: I didn’t enter anywhere on the sites using the VK account, I didn’t use anything, I just looked. How can such tracking be implemented at all? My page in VK is not named with real "name and surname", but with a pseudonym. After receiving this message, I decided to answer "what kind of spam is this", not really hoping for an answer, because. believed that it was just a robot, but the answer was, they say, "this is such a service."

Answer 1

Almost certainly it is not related to vk. There are special services, the code of which is installed on a large number of popular and not so popular sites. If you somehow proved yourself on at least one of these sites, then everyone else knows about you too. Such services can also automatically collect information about you from social networks and give a complete profile to those companies that use their services.
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