More than anybody, David Ogilvy was a master of delivering value in his ads. In his famous house ad "How To Create Advertising That Sells", he gave away 38 key pointers to help you create more effective advertising. All for free, published in newspapers like the Wall St. Journal & New York Times. Beyond that, he wrote about a dozen more ads following that same exact "How To" formula.
Another example of value-driven advertising is his "Guinness Guide To Oysters" ad, where he educated you on all different types oysters with up close images of each oyster in a neatly formatted design, ideal for hanging up in a restaurant or bar. In fact, if you look at the bottom of that ad, as well as others he's written, he even provides an option to buy a large poster of the ad.
Why is delivering value in your copy an effective strategy? In the case of print advertising or direct mail, making the piece valuable decreases the chances of the recipient throwing it away. When there's value, they're less likely to view it as a sales message.
The key is, you also have to tease & leave out intriguing info to make them want more. You never give away everything, but just enough to impress & mask the sales message so it flies under the radar, yet still acts as a strong selling device.
