Despite an unprecedented increase in spam during 2003, email marketing is still an effective way to reach existing customers and contacts with a marketing message.

According to the 2003 DoubleClick Email Trend Report, legitimate marketers continue to get strong performance from email.

DoubleClick reports that on average, 88% of marketing emails are delivered to the intended recipients. About 37.2% of those who receive the message actually open it. And of those who open the email, 9.2% on average click through the links to the underlying marketing messages or offers.

These figures can vary significantly depending on the type of product/service being promoted. The following figures give an idea of how much the figures can vary based on the type of message and the product or service being pitched.

DoubleClick's figures are pretty reliable because DoubleClick is one of the oldest and most established of the online behavior tracking tools. They track statistics on billions of email messages. With so many messages being tracked, you get a comprehensive picture of online behavior.

Of course, email marketing is best for marketing to existing customers and contacts — those who already know your company. You can remind them about your company, and hopefully get them to purchase more from you.

Email is not, however, useful for trying to turn a complete stranger into a customer. Sending out millions of hilarious and absurd messages such as the one I received the other day (entitled "Anita, are you frying chickens?"), or sending out gibberish combinations of letters, numbers and words just to beat the spam filters — well, that's not marketing, that's a pestilance.