In the era of social media e-mail campaigns are forced to the bench. At least most of short-sighted "marketers" believe that. But that is not true.
Your most loyal followers and customers are not the ones who likes your pages on your Instagram feed. A dedicated fan subscribe on your newsletters, because they want to hear your true stories. They understand your inside jokes. In this platform you can truly build up an honest, value-based relationship with them.
E-mails are shiny gems in your range of channels, since only true fans take their time to read newsletters. And without a doubt they are your most precious ones.