I have a website that I manage myself on a VPS, so in theory everything should be under my control. I have no advertising whatsoever -- in fact, the only external script I run is for Google Analytics:<script>  (function(i,s,o,g,r,a,m){i['GoogleAnalyticsObject']=r;i[r]=i[r]||function(){  (i[r].q=i[r].q||[]).push(arguments)},i[r].l=1*new Date();a=s.createElement(o),  m=s.getElementsByTagName(o)[0];a.async=1;a.src=g;m.parentNode.insertBefore(a,m)  })(window,document,'script','//www.google-analytics.com/analytics.js','ga');  ga('create', 'XXXXXXXXX', 'YYYYYYYY');  ga('require', 'displayfeatures');  ga('send', 'pageview');</script>I use Ghostery in my browser to tell me what scripts are running on what pages. Fine. Accessing my own page, usually, shows exactly one result: Google Analytics. Except sometimes, it will display two results, Google Analytics and Doubleclick. This does not appear to be URL dependent: refreshing a single page will sometimes show Doubleclick, and sometimes not.It is not malware related: I experience this on all of my devices, as do my users (who in fact reported this to me, prompting me to install Ghostery).Why is this happening?
Why does Doubleclick get added to my page (sometimes) when I use Google Analytics?
google analytics;doubleclick ad exchange
Doubleclick appears when you use the demographics feature (ie. ga('require','displayfeatures')).