E-mail marketing - on the Internet - is popular with companies because:

• Compared to other media investments such as direct mail or printed newsletters, it is less expensive.
• It is instant, as opposed to a mailed advertisement; an e-mail arrives in a few seconds or minutes.
• It lets the advertiser ‘push’ the message to its audience, as opposed to a website that waits for customers to come in.
• It is easy to track. An advertiser can track users via web bugs, bounce messages, un-subscribes, read-receipts, click-through, etc.
• Advertisers can reach substantial numbers of e-mail subscribers who have opted in to receive e-mail communications on subjects of interest to them.