I have two websites; A and B. I have hyperlinked linked these sites via advertisement banners and have contact forms on both. When people contact me through Website B's Contact Form I believe they are actually visiting Site A first and then after clicking through to Site B they then click the contact form of Site B - but they actually, initially, came through Site A.Is there a way that I can monitor which site they initially came from?I feel like it can be done but can't figure out how to do this. I feel like it would be through tracking cookies (eg. via ClickMeter), Google's Tag Manager or somehow through the PHP Contact Form but can't quite yet understand how to do it.Any ideas? 
Tracking users between sites using contact forms
tracking;cookie;forms