You add an advanced pixel tracking snippet of HTML code to each page you want to track key value pairs for. The click trackers then use the information provided by the pixel trackers to determine what visitors visited what pages and record the key value pairs you assigned to the advanced pixel tracker.
The HTML code loads a 1×1 clear image on the page and sends back all the needed data on the visitor along with the key value pairs you assigned to the advanced pixel tracker loading the page.