Everywhere I turn, I'm being asked to weigh in on the issue of whether copy should be long or short in a sales letter. I receive countless newsletters on copywriting and marketing, and they are all still debating the issue.
I doubt that the question will be answered definitively, but after hearing from other Internet copywriters and after considering the issue myself, I've learned that if you follow three guidelines, the issue of length will become almost irrelevant.
Guideline #1) TELL PROSPECTS WHAT THEY WANT AND NEED TO KNOW TO MAKE A BUYING DECISION.
Interested prospects will read even a sales letter of several pages long if they are interested and if your sales letter has good content. Many of us are more interested in telling prospects what WE want them to know. But we should all be telling prospects what THEY want and need to know.
Guideline #2) OMIT NEEDLESS WORDS.
This guideline is actually Rule #17 from Strunk & White's famous little book on writing, _The_Elements_of_Style_. (If you write, you really should read this small but influential book.)
Anything that doesn't have a direct purpose or work toward winning over your prospect should be cut out. I don't care how much you want to tell them about what a great reputation your company has and how successful you were last year. Unless that information takes the reader one step closer to buying (admittedly, sometimes it does), cut it.
Do the research and know your target audience. Then, write with their needs in mind. Write everything your prospects want and need to read, but write ONLY what they want and need to read. Cut the rest.
Guideline #3) TEST. TEST. TEST.
This is the best indicator of how long your sales letter should be. If you don't like to test, you have to rely on luck. Not a good idea. Put together the best sales letter you can with everything a prospect needs to know to make a buying decision, cut out anything that's not essential reading for your prospect, then run it. Record the results. Rewrite a portion of the letter. Test again. Record the results. Keep doing this until conversion rates improve and you'll know how long your sales letter needs to be. Of course, this kind of testing is much easier online than in offline direct mail, but it needs to be done. (Offline direct mail will probably require a split mailing.)
Although many people will tell you that "research has shown longer sales letters pull better," the only research you should be paying attention to is your own. Long sales letters don't pull well for everyone.
There's an easy way to answer to the question of how long or short a sales letter should be. (It's the same for other similar questions of tone, diction, and how much text you should emphasize.) Determine the needs and desires of your readers and you'll have your answer.
Matthew Cobb is an independent copywriter/consultant. Contact him at contact@cobbwriting.com or learn more about Sales Letters by Matthew Cobb by visiting his Web site at www.cobbwriting.com/salesletters, and sign up for his free monthly e-publication, The Seductive Sales Letter Clinic. | 
