Almost every public website rely on Google Analytics for statistics. CloudFlare offers an app to manage the tracking system without edit your own code. It is a very useful feature but has some limitation.
Recently I worked on a network of blog (WordPress-based) available under different (and strange, I know) urls:
Each urls is a different WordPress installation with different content management teams from somewhere in the world which share the root domain. An hour after I had activated CloudFlare the content management teams of blog 2 and 3 reported me a fall of the visits. Websites were online and after 30 minutes of search (and a little headache) we found the problem: The UA code of Google Analytics were all pointed to the one of blog 1.
The CloudFlare app is very useful but doesn’t let you manage custom path and subdomains. It overwrite each occurrence of Analytics code with its own! Use it with caution 😉