Return of the Lowest Common Denominator

Many things learned in high school are never to be used again. But you can apply some basic principles of high school mathematics to catalog measurement, says Mike Grant of Scarsdale, NY-based catalog consultancy Michael Grant Direct.

The concept of least common denominator, for instance, enables you to compare catalogs of different page counts, he says. For those who don’t remember, this concept is applied when you have got two (or more) fractions, each with a different denominator, that you want to add or subtract. The least common denominator is the lowest multiple of the denominators that they have in common. If you want to add one-fourth plus one-third, for instance, the least common denominator is twelve: One-fourth is the same as three-twelfths; one-third is the same as four-twelfths.

Demand per catalog is the most commonly used metric to measure catalog mailing productivity. The dilemma that many catalogers face is what to do when they have catalogs of different page counts. It is here that you apply the least common denominator principle.

Use demand per circulated page as the least common denominator to put all the catalogs on a level playing field, Grant says. This enables you to compare the productivity of an 80-page catalog with that of a 72-page or a 120-page catalog. Just be sure to account for price point differences as well as density, Grant adds.