This research was planned in order to check the observations made based upon theoretical works on the complementarity of magazine and television advertising. Although few media-planners doubt the beneficial effects of this complementarity on ideas such as coverage and GRPs, little work has been done which effectively demonstrates that this complementarity also contributes to improving a plan's qualitative performance ; i.e. it's impact on the targets. Thus if almost everyone is convinced that, for an equal budget, replacing a number of television spots by magazine advertisements improve the plan's performance, the survey aims to show that this also improves the campaign's performance . Beyond the punctual character of this research, the positive conclusions that it reveals are very interesting, for if they are considered alongside results from other surveys on media complementarity (e.g. the visual transfer shown between T.V. and radio), it can be concluded that a combination of several media is always more efficient than one single media, with an equal budget. The research shows that this rule applies provided that a minimum level of effectiveness or, in other words, a certain level of advertising investment, has been reached. Once this threshold is passed, it is clear that it is more opportune to generate impact by creating new sensations (by messages stemming from other media) which maintain the level of attention rather than cumulating with repetition which results in little marginal gain, or even, at worst, generates boredom and loss of attention.