Email marketing has had its ups and downs over the years. Originally email was exciting and it was just like getting a letter (or maybe not). We did however read every single line. Back then we only received a very small number of emails and they were more often that not useful or relevant, ideally both.
Over time as marketers do we ruin everything (stolen line from Gary V). Spam became a thing and any attention we game email became skim reading the title and if opened even more skim reading of the content.
Still number 1
Today email is still a primary inbox among many we just have much better filters both physical and mentally. It does however still surprise me just how important our inbox is to us and how it can drive our lives and productivity.