That's a question as old as the profession of copywriting.

There are good proponents on both sides. Some argue that in the age of video games and 30 second commercials, people just won't wait to get to the bottom line. They want instant information. Those who maintain that shorter copy is best site higher opt-in rates when the page is short and with a clearly defined the call to action.

Frank Kern's recent Mass Control 2.0 campaign is a perfect example of the short is better school. The longer opt-in page attracted a healthy 18% conversion rate, but the short opt-in page with little more than a big red arrow and a box for an email address drew 40% or more right out of the gate.

On the other hand, copy that tells a compelling story can draw the reader (or listener) right in and rivet attention to the very end. You have a better chance of establishing your authority on the subject and giving prospects a picture of your personality. Long copy is best for establishing authority and likeability.

In one of the pre-launch videos in Frank Kern's recent campaigns he spent almost an hour going over one of his long format sales letters that drew in hundreds of thousands. He pointed out the sub-story in bold print spread throughout the sales letter. It told a story within a story and gave people who just skim sales copy all the essentials without all the verbiage. This ingenious technique combines the best of the long and the short copy methods.

So, in response to the question, which is better, long or short copy, it simply depends. Make the copy as long as it needs to be to tell the story and no longer. Make it as short as it needs to be when all you are trying to do is get an opt-in for a simple or free offer.