Driven by mobile and social’s influence on email marketing, here are four key trends to keep in mind as you craft your subject lines this year: 1. Mobile continues to shorten subject lines. Because mobile devices display fewer characters of a subject line than their webmail and desktop email client counterparts, the growth of mobile email reading is putting downward pressure on subject line lengths. Thirty-one percent of marketers say at least half of their emails are read on mobile devices, according to our 2015 State of Marketing report. And, somewhat shockingly, another 23% of marketers are unsure how often their emails are viewed on mobile. Taking those two together, it’s likely that around 38% of brands have their emails read on mobile devices at least half of the time. Get the full story at Exact Target