Email marketing is a form of direct marketing which communicates commercial messages to an audience. Broadly, every e-mail sent to a potential or current customer could be considered e-mail marketing. However, the term is also used to refer to:

• Sending e-mails to enhance a relationship with current or old customers and to encourage customer loyalty and repeat business.
• Sending e-mails to acquire new customers or to convince old customers to buy something immediately.
• Adding advertisements in e-mails sent by other companies to their customers.

Advantages

E-mail marketing is popular with companies because:

• Less expensive than traditional marketing.
• Return on investment has proven to be high when executed properly and is often reported as second only to search engine marketing as the most effective internet marketing technique
• Instant.
• The advertiser can push the message to the user .
• Easy to track via campaign reports.

Disadvantages

Many companies use e-mail marketing to communicate with existing customers, but many other companies send unsolicited bulk e-mail, also known as spam.