Hello guys. I have an URGENT! task to create a referral system that works by viewing sites. It has to be based on viewing sites. But I don't quite understand the principle how it works? As far as I have noticed how those systems work - the base url of the site doesn't change (e.g. https://clickme.com/refer.php?r=2). So how is a site being viewed when someone doesn't leave a site of a referral system. Would be grateful for any ideas. Thanks in advance.