Ad dollars: Publishers Information Bureau estimates of advertising revenues, derived by combining official ad rates and published pages. It multiplies the rate magazines charge on their rate card by the number of ad pages they published. The resulting estimate is an imprecise representation of actual ad revenue because advertisers often get discounted prices from the rate card. Because of various discounts and incentives, experts say that actual revenue is often half what the reported ad dollars would suggest. For this reason we are not using these estimates.
Digital magazine (nonreplica): Where the basic identity and content are similar to the printed edition but the articles and advertising may differ. Free, unrestricted public access to a Web site does not qualify as a paid digital edition. (Audit Bureau of Circulations)