Research and testing One thing makes the difference between Direct Marketing and other disciplines. You can count your results. Not to take advantage of this is madness. Testing alone is not enough. It will tell you what happens.
Research can indicate what is likely to happen and why it happened.
Targeting No product, however brilliant, will sell to the wrong people. And no creative treatment, however stunning will succeed if it isn't seen by the best prospects. A poor product or message sent to the right prospect is better than the other way round. In the prospect's life e.g. marriage, new house, birthday. These are critical to targeting.