Given that around 50% of emails are opened on mobile, all of the emails in the study needed to be responsive, have a single column of live body text, along with a heading. I collected statistics at three widths: full-width (desktop), mid-sized (450 pixels) and small (320 pixels).
With a sample group of 50, I’m not expecting statistical significance; I just wanted to identify some trends. By “average,” I am referring to the mean; the most popular is the value that occurs most often; and in some cases I note the median or middle value. All of the emails were deployed between November 2014 and January 2015, when I carried out this work. I used tools such as WhatFont, Charcounter and WebPagetest. I haven’t had time to triple-check it; feel free to email me anything wonky.