To extract the "Most popular tags “ KPI, the cheapest and most effective solution is to use an HTML code for a Custom JavaScript variable in a Google Tag manager tag.

The code should dig into the top-page-tags class of the Document Object Model (DOM), extracts the inner HTML that starts with *# *and then return it as a comma-separated string. It shouldn't take much time of one of our superstar devs to get this code...

Once we got it, the Analytics gang will use this code in Google Tag Manager (GTM) to pass the value to a dataLayer variable, and use the return value as custom dimension