Email marketing is a form of direct marketing which uses electronic mail as a means of communication.
 

Advantages

Email marketing (on the Internet) is popular with companies for several reasons:

• An exact return on investment can be tracked ("track to basket") and has proven to be high when done properly. Email marketing is often reported as second only to search marketing as the most effective online marketing tactic.
• Advertisers can reach substantial numbers of email subscribers who have opted in (i.e., consented) to receive email communications on subjects of interest to them.
• Over half of Internet users check or send email on a typical day.