Do you want to know what one of the single worst mistakes you can make when writing your copy is?

A mistake that, while technically small, can have terrible consequences not only for the response of your ad...but also the way your customers think and talk about you?

A mistake most of us are bound to make at some time if we aren't careful?

The mistake I'm talking about is this:

Promising to reveal some sort of secret or "insider" information in your ad...and then not doing it.

In other words, starting an ad out by saying something like:

"In this very letter you're holding in your hands I'm going to show you some genuine money-making secrets you can start using today...."

And then doing nothing but teasing and selling, never actually revealing anything.

Look, this may seem obvious, but it happens all the time. And usually not on purpose.

And while it's no mystery that promising to reveal information in an ad increases readership...if you don't actually reveal anything (and just tease, tease, tease instead) you're going to look like either a liar or a flake to a lot of your readers.

Sure, the really hot prospects -- the ones who will buy anything related to the subject you're writing about -- will probably buy.

But what about the people on the fence?

Well, they may not be so eager to give you their money if you can't even deliver on one little secret or promise you told them you'd give them.

Bottom line: Be careful you don't have an editorial lapse like this. In some cases, it may have no effect on your response whatsoever. But there will also be times where it can kill your response and leave you wondering why.

Ben Settle is an expert copywriter and direct marketer. If you liked this article then check out Ben's website at http://bensettle.com -- and get your hands on over 500 pages of advertising ideas, strategies and tactics just like this one -- as well as rare swipe file ads and hot marketing information not easily found anywhere else.