Purpose: This paper aims to respond to issues posed in the four commentaries on Armstrong, Dy, Green and Graefe (this issue) regarding the immediate usefulness of that paper's test of advertisements' compliance with persuasion principles, and regarding the need for further research. Approach: Address commentators' concerns using logic, prior research findings, and further analyses of the data. Findings: The superiority of the index method remains when a simple, theory-based, alternative weighting-scheme is used in the index model. Combinations of three unaided experts' forecasts were more accurate than the individual forecasts, but the gain was only one-third of the gain achieved by using the Persuasion Principles Index (PPI). Research implications: Replications and extensions using behavioral data and alternative implementations of the index method would help to better assess the effects of judging conformity with principles as a means of predicting relative advertising effectiveness. Practical implications: Advertisers can expect more accurate pretest results if they combine the predictions of three experts or, even better, if they use tests of compliance with persuasion principles, such as the PPI. The PPI software is copyrighted, but it is available and is free to use. Originality/value: New analysis and findings provide further support for the claim that advertisers who use the PPI approach proposed by Armstrong, Du, Green and Graefe (this issue) to choose among alternative advertisements will be more profitable than those who do not.