Your email marketing can succeed or fail based on the words you place in the subject line. That's where the whole "read or delete" debate begins in the recipients' mind. Make no mistake about it, nobody reads every piece of email in their inbox anymore. Spammers killed that. How many male enhancement emails can you read ?

As the sender, you have to get the attention of the sendee. A subject line that stands out is the first step, and there are a number of approaches to be considered:

Be brief. Think newspaper headline. Better yet, think magazine headline. Catchy but short. Nike did it with eight letters.

Use the word free, but mean it. Free is oft-times a throw away word that means you have to buy something else to get to the free part. Don't insult your readers or play games with the free offer.

Test, a lot. Like every other part of your email campaign, test to make sure you know what emails are getting opened. If the subject line isn't driving people to read your e-communique, change the verbiage.

Make the subject line time sensitive. Use phrases like, "the first 10 people to respond"--"offer good til midnight", "free shipping today only". It creates some urgency and increases the likelihood of having your message read.

Avoid spam words. Make sure you test your subject line and email with a content checker. It will identify words, phrases or problems that could land your email in the spam filter.

Be honest. Don't overpromise in your subject line headline. Can you really think and grow rich in 30 days?

Like all aspects of advertising, the race is won by he who differentiates himself--stands out from the crowd. Email campaigns are the same. Work on your subject line. Craft it and then test it. You'll know when it needs some work. You'll know when you've got it right.