The question remains how much weight is sufficient?
The short answer is it depends on target audience, creative execution, product category etc. However PPA has attempted to provide a consensual view of sufficient to aid planners in their approach to magazines. Erwin Ephron . since the first exposure is most cost-effective, if we can reach a large number of consumers without piling-up second and third exposures, we can use the frequency-money to advertise for more weeks, to reach more consumers who are ready to buy in those weeks. The caveat is we need to do this while maintaining a weekly reach of 35% to 40%, a monthly reach of 65% to 70% and a quarterly reach of 80% to 85%, so we talk to enough people to have a measurable effect on brand sales. The Shelf Space Model of Advertising Erwin Ephron (www.ephrononmedia.com) Using the highest sum of weekly reaches as a planning goal, results in schedules of moderate GRP weight and more weeks of advertising. There is a complication in the need for a reach threshold. A minimum target reach of 3
