Tracking stuff came as soon as you could communicate asynchronously with a server, really. It became widely known and a plague in the 10s but it started as soon as Ajax was available. Keep in mind that Google and most of the websites were free and ads driven almost from the start because that was the only way to create a critical mass of users.
Tracking stuff came as soon as you could communicate asynchronously with a server, really. It became widely known and a plague in the 10s but it started as soon as Ajax was available. Keep in mind that Google and most of the websites were free and ads driven almost from the start because that was the only way to create a critical mass of users.