"Basic business principles dictate that purchasers insist on receiving their money's worth. Yet assessments of return on advertising spend all too frequently bases calculations on total circulation, without any core circulation adjustments.
"The best value for advertising is found in publications where the variance between cost-per-thousand (CPT) total circulation and CPT core circulation is least or, ideally, zero. I would recommend that all advertisers conduct a core circulation exercise before spending the money, as they may be called to account when the sums are done," says Gibson.
She says while advertising agencies tend to appreciate the relevant subtleties, some advertisers inadvertently overlook what should be a key factor in determining the optimum return-on-advertising spend.