keeveek: GOG is not sending any cookies to google or any browser data. How would google take it and connect it with your order id?
In two ways:
* Google Analytics'
Javascript code (which is run by GOG's thank-you page) sets Javascript cookies. It would be straightforward to access (or modify) cookies for other Google domains by including links to them (with the cookie contents embedded in the link).
* Using
browser fingerprinting, which should work well with most GOG users being on broadband connections with static IP addresses. Defeating browser fingerprinting is *hard* - you need to use shared proxies and modify your User Agent to something generic to do that.
keeveek: GOG is sendind that data from GOG's servers site, not your pc. In other case, they would have your IP address also, but they don't.
When you get the thank-you page the follow events happen:
*your browser receives the HTML from GOG.com;
*your browser executes that HTML to create the page you see;
*where that HTML includes links to other sites (like the social network links at the bottom), your browser will connect to those sites as well;
*the analytics code on GOG's page causes your browser to connect to Google Anaytics and submit data on your order.
So Google do get your IP address, your browser details and effective access to any Google-owned cookies set previously.