Is it possible to track known contacts on our website without them having to click an email link that passes through their identity? So if they are already cookied, will they be tracked as a known contact if they return to the website without clicking a link in an email? Secondly, is there any way to track a link with UTM parameters in a social post and show this as the starting point of how a known contact arrived at our site. I know this is standard Pardot functionality but I cant seem to find this functionality explained clearly for Marketing Cloud. We want to be able to add a link to a social post and if the person clicking the link is known in our database, attribute that link click to them. Any guidance appreciated.
With MC Personalization Builder you further collect the tracking data into Data Extensions. You find more information in the help section here.
Regarding your second question about UTM parameters, Web Analytics Connector offers these features. It's a lot more complicated than Pardot offers, but it certainly has a lot of features and allows for the things you want to do. More information on MC Help here.