Testing, The Dirty Dozen (1,848 words)
Calculate what size mailing you'll need to conduct to get results that are statistically confident within a certain margin of error. Be careful not to test at an unreasonably high confidence level with too tight a margin of error—if you do, you will end up mailing far more pieces than necessary. Usually a confidence level of 85 percent to 90 percent is adequate.
If all this sounds like Dutch to you, pick up a book on statistics or even a basic direct marketing text. It will provide confidence tables and the formula to determine appropriate mailing and calling sample test sizes.
Bonus Tip: Back Test
Consider this a baker's dozen … lagniappe … a little something extra. Too many direct marketers neglect to back test. When a new element or breakthrough concept beats your control, that's great. But don't forget to retest the new winner against the control. Results can vary, so make sure you do indeed have a true winner.
A well-designed and well-orchestrated testing strategy can reap huge rewards for just about any direct marketing enterprise. This piece only touches the surface of a deep and disciplined approach to testing.
If nothing else, remember this from Malcolm Decker, who came up with two inviolable rules of direct marketing:
Rule #1: Test everything.
Rule #2: See rule #1.
Shawn D. Morris is president of SDM Associates and affiliated with JCG Ltd., an international direct marketing consulting group specializing in the insurance industry. He can be reached at ShawnMorris@JCG-Ltd.com or (615) 308-3590.