In the past circulation was treated as top-secret information. Naturally firms looking to advertise wanted an objective figure in order to judge how effective their advertising might be.
由於以往各報發行量一直被視為機密，在報紙刊登廣告的廠商自然欣見有個公開的參考數字，以便推斷他們的訊息可能產生的效果。