The hidden purpose of emailing to your customers regularly is to build on the trust and credibility that you have created, building a relationship so they won’t forget you and go to a competitor when they are ready to buy.
Sending useful, interesting and beneficial emails to the subscriber is the key. Quality email marketing is not about selling to your customer list, but educating and building the relationship. Then when you do want to send a new product or service offer, your prospects will want to buy from you.
Contacting personal customers who are already warm to you. Getting trackable click and open rates, sending secure targeted messages with news and special offers. Email marketing is a very secure form of communication, where social is not.