The Basis of Direct Marketing
What mystified me about direct marketing was its science. "We can produce measurable results." I was told. "We can know what is working!" And to a large extent that is true. I was told that you could make your own way in this world, as long as you could "beat control". Since I have much more training in the philosophy of science than in marketing, so it seemed a natural fit.
Sharper Image began with a runners watch. The first ad done all by itself, made money. Richard Thalmeier, the founder, tried more ads... kept track and away he went. And back in the '80's, my business was mostly in teaching non-direct marketing companies the basics of measurement and testing. It worked best when it was kept simple... and then the claims of the Direct Marketers started expanding....
Here is a solid article on Direct Marketing I think you'll enjoy it.