I found a great example of a Heavy-Tailed Frequency distribution in my performance data today.


This clearly shows how data in the wild can be distributed in a non-normal fashion. In this case, there is a very heavy weight on the end of the tail, not simply a few straggling outliers.
It has become very unusual to find sites that exihibit this degree of heavy-tailed behaviour  over the last year. When I started in this industry, this was more the norm than the exception.