How Many Magazines Should be on Your Schedule?
There is absolutely no doubt that concentrating your advertising in a few publications provides a significantly greater return on investment than spreading the same number of ads across many.

First, consider the issue of coverage. Studies undertaken by McGraw-Hill's Laboratory of Advertising Performance based on five different fields show that, on average, if you are using five publications in a given field, the leading publications will provide over half the coverage provided by all five together - an average of 66 percent. Succeeding publications add increasingly fewer readers; the fifth publication is shown as adding only an average of 17 percent of the total coverage.

Next, consider duplication. The leading publication, as mentioned, provides 66 percent of the total coverage; the second publication adds 20 percent more unduplicated readers. And the third, fourth, and fifth publications add only seven percent, four percent and three percent unduplicated readers respectively.

When the cost factor is recognized the picture becomes even clearer. Cost and coverage are not added at the same rate. For example, the fifth publication on the schedule adds only three percent, but each of those new readers costs 18 times as much as a reader of the leading publication.

There's much more supporting research available. It all points to the same conclusion: Concentrate your advertising in the top publications in your field.