Myth # 1. People Won’t Read Long Copy.
One of the most pervasive marketing myths is that you should write short advertising copy because people will not read long copy. However, studies have shown this is wrong. The truth is people will read whatever interests them–they will read long books, articles and letters.  The more you gauge their interest, the more likely they will keep reading. The key is attracting their attention with a powerful headline and using personal communication to keep them engaged.
The secret to good advertising copy is that it is nothing more than salesmanship in print. Would you tell your salespeople that once they are in front of an interested customer they only have one minute to get their idea across or that they can only tell half the story? Of course not. The same goes for copy.
The key is neither to write long nor short, but to cover all the points in sufficient detail and in a manner that encourages interested people to read on.
Your goal should always be to provide all the information a prospective customer needs to know before making a buying decision. A copy could be long if you are introducing a new product that buyers are unaware of or it could be short if it is a national brand supported by TV advertising—for this, you may need nothing more than a picture of the product and a price.
The truth is that no matter how good your flyer is, the majority of people who see it are not going to read it. Unfortunately, most will be immediately discarded and what is left may be read by those sufficiently interested to do so. While some flyers will be read right away, others are often put aside for later reading and will only be picked up if the headline or grabber catches the reader’s eye. It is for this reason you need to find a compelling way to provide the prospective buyer with sufficient information and remove any hesitation from his or her mind.
 Hesitation lies from any unanswered questions prospective buyer may have or from inadequate information. These lose far more sales than long copy. If you do give the readers more than they need, there is a stronger possibility they will buy from you.  However, if you provide them with insufficient information, it is almost certain they will not buy. You have to make it easy for them to purchase items and you have to remove the causes of hesitation.
Studies conducted on how people read advertisements and direct mail show that readership drops quickly after the first 50 words, but stays high from 50 to 500 words. This means people who are not interested or engaged will discard your advertisement in a hurry, but interested prospects will read every word, trying to learn as much as they can about what you have to offer.
Similarly, I ran a test selling service contracts to householders in which I used an eight-page letter and a one-page letter. Both letters were sent to the same audience and even though they both offered the same service, the longer letter generated three times the response than the shorter one.
The key is neither to write long nor short, but to cover all the points in sufficient detail and in a manner that encourages interested people to read on.
Your goal should always be to provide all the information a prospective customer needs to know before making a buying decision. A copy could be long if you are introducing a new product that buyers are unaware of or it could be short if it is a national brand supported by TV advertising—for this, you may need nothing more than a picture of the product and a price.