Marketing can be made in several ways in which this E-mail marketing is also among them. E-mail Marketing invloves the standard commercial interation through E-mail. Here we approach the customers by using option like "Subscribe" so once the mail is sent to the potential customer accept and subscribe for particular event or task. This way we generate a lead. We do not send this email for subscription but also for advertisements, request businees, donations, and even more. So it helps to build loyalty and trust.
This is one of the best and direct way we use to approach public to perform particular task like purchasing or for advertising also.