Email is the best possible way to be n constant communication with your entire customer base.
Broadcasting, Templating or Freestyling?
Do you send out massive newsletters every month? (broadcasting)
Do you have set templates that you use for generic sales emails, ones that cover the exact same bases every time?
Or do you write each and every email, by hand, as you get around to it?
No matter which way you are already doing it, there is always going to be a better way. Email marketing is a dynamic process of finding out what works best in your industry and with your database!