If you're using e-mail to generate leads or make sales, you're probably spending a lot of time honing your message and making sure that it's persuasive. But do you give equal time, thought, and attention to the short "SUBJECT" line that introduces your main message?

If you don't, then be afraid. Very afraid. You see, it doesn't matter how compelling your e-mail offer is, or how brilliantly your message is written. If your subject line isn't working right, your e-mail will never get opened and your campaign will be a failure.

That's right. The humble little subject line that announces your e-mail to the world has an enormous influence on campaign results and can make or break you.

Want to handle subject lines the right way? Here are some thoughts that might prove extremely useful . . .

1. Think of the subject line as if it were an envelope.
When you're creating a paper direct mail package, you know you have to come up with a killer envelope. If the envelope doesn't get opened, the letter doesn't get read and you don't make the sale. Same thing with the subject line. It determines whether the prospect will read your message or trash it.

Of course, getting someone to open a paper envelope is a heck of a lot easier than getting past the subject line. Why? Because with a paper envelope you have plenty of space to write teaser copy and add photography or illustration if it's appropriate. You can create something unique that stands out from all the other mail in the pile and screams out benefits that will get the prospect to read the letter within.

Subject lines all look the same and have to be kept short. (Never exceed forty characters including spaces.) This means that every subject line must communicate extremely quickly. We'll take a look at how to do that in a minute, but for now, start thinking of the subject line as one of the keys to e-mail marketing success - not an afterthought!

2. Subject lines are well worth testing.
Robert Mendez (www.nethawk.net) is an e-mail list broker/manager who handles countless e-mailings and is a great source of information. I asked him about his take on subject lines. Here's what he said, "You should always test subject lines if you have enough names. Five thousand names is the minimum you need for an e-mail test cell. It's worth doing some testing because a strong subject line can double the response."

Let's look at that again on instant replay! "A strong subject line can double the response" - increase it by 100%. In other words, a 4% response rate can turn into an 8% response rate just by using the right subject line!

3. Some thoughts about saying "FREE" in the subject line.
Some people hesitate to use the word "free" in the subject line because they're afraid they will turn people off. For example, in an issue of Softletter, Michael D'Arrigo, Direct Marketing Manager at ScanSoft, is quoted as saying,"For us, we've found that a subject line with 'free' is the kiss of death. It will be viewed as spam and won't be opened."

Email marketers also have the related concern that if they use the word "free" in the subject line, a filter will kick out their message and it will never get read. I personally believe that this is just another suburban legend and that you really don't have to sweat it. True. There is some filtering, based on IP numbers, that takes place at the ISP level. And some corporations do some filtering. And, yes, some packaged applications let consumers use filtering. BUT this is only a big problem if you're selling business-to-consumer junk!

I believe that if you use "free" in the subject line, in well-targeted B2B e-mails that offer the prospect something of value, your message will sail right through unfiltered. Let me add that I know as a personal FACT that one of high-tech's most aggressive e-mailers uses the word "free" in the subject line and that this line is the consistent winner against other subject lines in rigorous head-to-head tests.

The bottom line? I would not give up on one of the most motivating words in our language because of spam or filter fears. You should definitely do some testing!

4. The right way to write subject lines.
Here's a mini case study that shows you how to think about putting a subject line together. Here's the subject line from an e-mail sent by a major marketer that targets small and growing businesses.

SUBJECT: Who's minding the store?

If you click through to find out more, you get to the message: "Small businesses are more vulnerable to crime than is generally realized, yet the risks to them are not publicized and too few take steps to protect themselves, says a new study. Don't wait until you are a victim of a crime - take steps now to thwart the bad guys. Here are a few tips" . . . etc.

So what's going on here? Well, the message itself certainly goes on to provide valuable information that small business managers should know. But instead of saying so directly in the subject line, the writer went for a "teaser" approach: "Who's minding the store?" This teaser subject line might be O.K. in an ad or flyer but is, I would argue, a big loser as a subject line. Why? Because no benefit is mentioned.

Let's rewrite the subject line and see if we can do a better job of motivating the reader. We could slice it and dice it a bunch of ways:

SUBJECT: Five ways to prevent store theft
SUBJECT: How to improve store security
SUBJECT: Stop store thieves in their tracks
SUBJECT: Don't let thieves steal you blind
SUBJECT: Crime prevention basics
SUBJECT: How to prevent store theft

You get the idea. The take-away message? The subject line is a vitally important part of e-mail campaign success and should be the subject of your close attention!