Direct Marketing Magazine - December 1996
Early Warning Systems for Direct Marketers
Paul V. Teplitz
Four decades ago, construction crews ventured out into the empty, frozen
tracts of the Arctic. Using the "high technology" of their day, they built
a chain of radar sites that could spot incoming aircraft hundreds of miles
away. This DEW Line (for Distant Early Warning) provided 3-4 hours' advance
warning of a Soviet air attack. Today, other weapons have long since replaced
the bombers and radars of the 1950s; but for millions of people, the DEW
Line remains a symbol of the safety and added sense of control offered by
early detection of coming events.
A small but growing number of direct marketers use the DEW line idea in their
businesses by pretesting their offerings a few weeks or months before a major
selling season. With this input, they scramble for more supplies of hot items,
head off production for slow-movers, adjust prices, and generally manage
operations in coming months with fewer surprises. The idea is particularly
helpful for companies with short, intensive selling seasons such as Christmas.
When it comes to advance testing, direct marketers have a big advantage over
others. To conduct a test, all they truly need is the printed mailing. They
avoid any need for warehousing, manufacturers' minimums, handling of
goods, and the like.
Do You Need Early Warnings?
Suppose you had a radar that could detect customers' interests in your
products a month before drop-date. What value would such alerts have for
you? Obviously, it depends on many factors. For Christmas toys, the selling
season is short; customers will not wait for backorders and competition
is intense. Under these conditions, an extra 4-6 weeks of advance planning
should have high payoff, particularly in a better ability to "chase"
hot items. For ongoing staple items, such as office supplies, underwear,
or most blue jeans, the risks of surprise are low, and so will be the value
of advance alerts. Companies that sell fashion apparel, short-season gift
items, or long lead time items have shown the greatest interest in getting
advance readings on their market. An early alert can tip the balance between
a crisis and a striking success, as this cataloger found:
A maker of branded apparel introduced a "fun" product unrelated
to its regular line -- a teddy bear. A mid-level manager came up with the
idea, thinking customers might like to give it as a Christmas present. Other
managers liked the idea, but lacking any experience in the "stuffed
animal" category, they wrestled with the question of how many to make.
Finally, they ordered an amount everyone agreed was conservative.
By good luck, a few weeks later the company conducted a survey on new products
that included, among other items, this teddy bear. Customers "bought"
it at more than five times the forecast level. Inventory buyers scrambled
to increase supplies, and when Christmas was over, they had sold almost
seven times the original forecast. Without the early alert, managers felt
they may have met one-third of that demand.
What's In An Early Warning System?
Let's assume you want to set up an early warning system for a new line
of products to be offered in next fall's mailings. Your company will
be introducing them in a few months, and your mission is to plan production
so that when they come out, you can meet the demand. There are three main
forecasting issues:
1. Market and economic conditions generally. Will people be in a spending
mood?
2. Customers' acceptance of the line as a whole.
3. Customers' item-by-item preferences within the new line.
The first issue, overall conditions, I will save for a future discussion.
This article will focus on the relative appeal of different products. Research
shows, by the way, that uncertainties in product appeal create far more costs
for most direct marketers than do fluctuations in overall demand.
If a supply of the product is available, the most accurate test is a
"live" test -- that is, mailing the actual offer to a sample of customers
and waiting for orders. Some direct marketers, thinking no other option was
available, have taken this approach but at considerable cost. Catalogers
have told us of new product tests that cost hundreds of thousands of dollars
for just a single product line. Obviously, such costs limit live tests mostly
to large firms.
Some companies use a 6 or 12-month variation of the live test. They
include test items as part of a regular (but small-circulation) mailing,
with the aim of analyzing results and "rolling out" the successful
items to their full list 6 or 12 months later. Accuracy suffers in
these tests, though, because of the long time until roll-out and because
the items' presentations, or the competing products in the catalog, may
change substantially by the time of roll-out. And costs, while lower than
the full tests above, still limit this approach to relatively few items.
More often, supplies of product will not yet be available and the test must
proceed with a survey or mock order form. Concern about the realism
of surveys, however, has caused some companies to rule out such tests without ever
trying them. "If test customers aren't spending real money, how
can their responses be relied upon?" or "How can the purchases
of a few early-bird customers tell us much about the masses to follow?"
To be sure, "artificial" measurements, such as surveys, do introduce
their own biases, but these distortions usually have a statistical regularity.
Some aspects of human nature are, after all, fairly predictable. The chief
biases that seem to appear in direct mail pretests are:
- Wishful thinking -- When they are not spending real money, respondents
tend to "buy" more items in surveys than they actually do. Not
surprisingly, this bias is greatest for high-price items and lowest (or even
reversed) for low-price items.
- Weather factors -- When customers answer questions about sweaters
in July, they will, no surprise, overstate their interest in lightweight
cottons and understate their interest in wool and other warm designs.
- Date-sensitive items -- Items that sell at certain holidays, such
as Easter or Christmas, tend to be underrepresented in tests conducted months
in advance. Customers' procrastination on gift items seems to increase
with each passing year.
In each of these cases, the key to useful accuracy is calibration of the
test. Repeat the test cycle a few times and you will have enough information
to adjust out these measurement errors in the future.
You can watch this process in action every couple of years on election night.
Based on exit polls, with proper adjustments such as voting patterns in ethnic
districts, the TV networks are able to call the winners of most races by
early evening, long before much of the vote has been tallied.
Performance

Illustrated above is the outcome of a customer contact test for a specialty
apparel catalog. This company mailed a preview of one of its catalogs to
a sample of customers, together with a questionnaire, about a month before
publication of the full catalog. Based on customers' responses, they
then updated the item forecasts prepared earlier by inventory buyers.
In this chart, the heavy line shows the pattern of buyers' forecast
errors without the test. The dashed line shows the pattern of errors if forecasts
were based purely on the test. Even with its inherent biases, such as respondents
not spending real money, this test reduced the standard deviation of forecast
errors by about one-third. It also reduced the number of large errors (more
than three times forecast or less than 1/3 of forecast) from about 9% of
the items to virtually none. The third, lighter line shows the forecast errors
that remained after the test results were adjusted to remove predictable
measurement biases. In this adjusted form, the test removed about three-fourths
of the variance between the original forecasts and the actual sales, across
dozens of items.
This test reached about one-fifth of one percent of the audience for the
catalog. Though overall estimates of the test's payoff were not computed,
the savings in just two items, unexpected hot-sellers, more than paid for
the test. Less tangible benefits included better customer satisfaction and
fewer strains with suppliers. Inventory buyers reported, as a major benefit,
the added confidence they felt when the test confirmed the appeal of items
for which they previously had felt they were going out on a limb.
Watchwords in Implementation
In building an early warning system, the following watchwords may help:
1. Match your design to the task. If all you need is an early indication
of interest in a few new items, an advisory panel of customers may do the
job. If the financial stakes are high, however, because perhaps the new items will
cannibalize sales from current ones, then you will probably want a quantitative
test with a statistical sample of consumers. Similarly, if you are introducing
a whole line of products, a statistically designed test will yield more reliable
information.
2. Measure everything (or almost everything). Keep detailed records of who
received the test, their RFM cells, dates of the mailings and responses,
different versions that were mailed, and so on. Much of the value in your
tests will come from comparing the results with various benchmarks, such
as previous tests, and comparing responses for different products or customer
groups. You may want to see if the test has any impact on recipients'
prior buying behavior. Good measurements also enable controlled experiments,
such as trying different prices. Usually, such measurements add little or
no costs to the project.
3. Give careful thought to the mailing package, not only the test items,
but companion items on facing pages, cover promotions, order forms, introductory
letters, and the like. In the case of catalogs, this means including competing
products, such as others in its own department or products customers typically
choose as substitutes. Though an item's appeal to customers will show
clearly in a pretest, competing products or near substitutes in the same
catalog may significantly shade the results up or down, hurting the test's
accuracy.
4. Take advantage of all your information sources. As useful as they may
be, customer contacts are only one among several sources of information reaching
you about a new product. Others include the opinions of product developers
and anyone else who has seen or worked with the product during its development
stages (such as suppliers), past histories of analogous products, and your
own intuitive feelings about the item. If you keep a record of these sources'
predictions, you will, over time, be able to calibrate their accuracy and thus
know how much weight to give them in the future.
5. Include some calibration points in your test. If you are testing the whole
catalog, it inevitably will include a number of "old classics"
whose demand is relatively predictable. If you are testing a solo mailer
or a fractional catalog, plan to give more attention to the selection of
other items you will include in the test and how you will interpret
their results.
6. Stick to one mission. Quite often in customer tests there is a strong
temptation to try myriad variations of the product -- to "tweak"
its price, features, ad copy or whatever, to arrive at the combination that
most appeals to customers. Unfortunately, this tweaking comes at a price,
in added sample or diminished forecasting accuracy. Such testing usually
serves a marketing purpose more than a forecasting one, so you will need
to consider its cost -- and value -- in that light.
7. As you gain experience with early warning measures, you can expect several
benefits from the learning curve. First, the mechanics of conducting the
measurements become easier, based on lessons from experience. Second, you
can compare the results of past tests with the products' actual sales results,
to better calibrate the measurement biases in the tests. From this analysis,
you can improve the correction factors to apply in future years. Or, you
might adjust the test procedure to reduce such effects. Finally, inventory
planners grow to accept the tests and act more decisively on the information.
An Added Bonus
An added bonus of our pretesting work has been insight into the effects of
display on performance of direct mail items. Not surprisingly, the pretest
findings frequently disagree with buyers' initial forecasts. In exploring
these discrepancies, the explanations frequently came back "lousy
shot" or "it's just a great picture." Over the years
these discussions have led to a variety of buyers' theories about the
linkage between display and demand. When tested statistically, about half
of these theories have proved accurate. They have been incorporated into
the adjustment models or pretests as well as buyers' practices in
pre-season forecasting. Other useful insights relate to the competition
among items in a department and promotional pricing.
Concluding Comments
Perhaps the most important lesson of all from early warning systems is that
it does not take long for organizations to catch on to their value. Once
people break the mindset that, "We can't do it," or "Nobody would believe
it," or whatever, the possibilities expand exponentially. We have seen companies
increase their testing programs by ten-fold or more over the course of a
few years. This growth takes place not only in scale but also in their degree
of sophistication, such as looking for ways to test items earlier in the
development cycle. Functionally, they are adding longer-range radars to their
DEW lines.
With intensifying competition and a faster pace of change in business, early
warning systems will almost certainly grow in number and importance. Just
like the Allies in the 1950s, aggressive companies will always want to gain
an edge over their competitors through better intelligence about their markets.
As the DEW line proved four decades ago, looking beyond the horizon can make
the difference between last-minute panics and being able to sleep at night.
If your company does not yet have an early warning system, maybe now is the
time to start thinking about how you might build one.