What's the most important part of a sales letter? Whether you're a copywriter who's writing direct mail, or a web promotion, you may be convinced that it's the headline. Not so.

Copywriting is both a craft, and an art, which you develop with your own experience and creativity. I cringe whenever baby copywriters are told to build "swipe" files -- copying others is not the way to write persuasive, selling copy. 

Read on to discover what's the important part of your sales letter.

1. What Results Do You Want from Your Copy?

Start by deciding what results you want. You (or your client) may want people to call a phone number, buy at a special price, or join a mailing list.

Whatever it is, write it down.

Yes -- WRITE it down. Stories about display ads which cost many thousands of dollars but contained no contact details are not apocryphal. They happen.

2. Your Headline Is Vital, But...

Copywriters hear that "the headline is the most important part of your sales letter", and go wild. They write outlandish headlines which succeed in getting attention. (Often sheer disbelief.)

Unfortunately, if there's a disconnect anywhere in your copy, people stop reading. Your copy must flow smoothly and logically from your headline.

3. The Only Job You Have: Keep Your Prospect Engaged

Most sales letters are long. Print letters may consist of three or more pages; web letters are often 16 to 20 pages long, if they're printed.

It's easy to lose your prospects along the way; don't. Keep them reading.

If you know the product, and you understand the market, that's not a problem, so make sure you research first.

And now, we come to the most important part of any sales letter.

4. The Call to Action!

Yes, it's the call to action.

Your headline needs to attract attention -- the right attention -- and if you know the product and the market, it's easy to write.

But unless you devote considerable thought-power to the offer, and the call to action, all your hard work and creativity is wasted.

Results are what count, and the call to action gets the results.