In late 1913,R.O.Eastman of the breakfast-food company Kellogg's told the Curtis advertising staff of a readership survey he had directed earlier that year.The survey was backed by more than sixty companies that,like Kellogg's,wanted“to know what we are buying.”That is,they wanted to know more about magazines'readers,especially how much duplication of circulation there was among the dozens of popular magazines.Eastman compared an advertising purchase to a purchase of coal,which was analyzed to determine its heating and power potential.“We cannot buy advertising that way,unfortunately,”he said,“but we ought to work toward that point-of buying and selling advertising by its heat units,by its power units,by what it will do.”The survey Eastman had directed consisted of a house-to-house canvass of 16,894 homes in two hundred nine cities and forty states.He said that such surveys were just a beginning.
“Advertising is a force;a wonderful,powerful,tremendous force,but it has not been weighted,measured or gauged.Not only that;we have not found,we have not devised,the weights and measures or the gauge wherewith to weigh,measure and gauge it.The first rudiments of the thing are before us.”“Tenth Annual Conference,”pp.13-36.Selling Forces,pp.210-213.Curtis took the hint from Eastman and other advertisers.The company first provided a detailed breakdown of its circulation in 1919,and through the 1920s and 1930s,it continued to expand its analyses of circulation,correlating Curtis circulation with such things as income tax returns,number of wage earners,value of products sold in an area and the number of passenger cars(both Fords and non-Fords).It mined the 1920 census for information about rent and other indicators of income.It also used its own research to further its claims of superiority over competing publications.See,for example,“Retail Dry Goods and Ready-to-Wear”;“Department Store Centers,”“Market for Electrical Merchandise,”“Rental Analysis in the City of Chicago”;and“Market Opportunity,”all in the Curtis“Dope Book.”In 1922,the company cross-checked the subscriber lists of the Post,the Journal and Country Gentleman from Ohio,Iowa and New York to show that the duplication of subscribers among the magazines was small.Curtis said that 4.9%of readers subscribed to both the Post and Country Gentleman and 5.9%subscribed to both the Journal and Country Gentleman.See“Duplication of Circulation Among Post and Country Gentleman Subscribers,”and“Duplication of Circulation Among Journal and Country Gentleman Subscribers,”Curtis“Dope Book.”