This was the article yesterday (click here).
There are a few things I need to follow-up on.
(1) If your vendor tells you that you do not need to execute Mail / Holdout results for catalog marketing (or for email marketing), find a new vendor. They are purposely hiding something from you (hint - it could be the truth).
(2) If your catalog marketing team is not conducting Mail / Holdout tests, ask them why. They must give you a credible answer. If you don't get a credible answer, be worried. You need to generate profit ... now.
(3) If your Executive Team says you cannot execute Mail / Holdout tests because you will lose sales, fine, execute small cell count tests over 4-12 months instead of large cell count tests each month. Executive Teams are frightened by sales declines ... they lose their jobs over sales declines. Their incentives/salary are at odds with your testing plan.
P.S.: (1) is probably most important. The Catalog Vendor Industry has a vested (and strong financial) interest in not executing Mail / Holdout tests. If you get pushback from your vendor today, listen carefully to the pushback they provide. Mail / Holdout tests in catalog marketing, made popular in the late 1980s, are easy to execute and quickly reveal truth. Why are folks afraid of the truth?