A decade of work in marketing meta-analysis has produced empirical gen
eralizations concerning parameters in models of advertising, price, di
ffusion, and consumer behavior. Results from these meta-analyses shoul
d replace the now discredited zero null hypotheses of such parameters
in future work. Probably more important than nonzero ''grand mean'' av
erage effects is an approach called Parametric Adjustability, which pr
ovides estimated parameter values for specific conditions reflecting m
arkets and research technologies. Systematic application of the method
ology can also help guide research along productive routes and away fr
om repetition of work which has little potential to add new knowledge.