In September 1989 a short but heavy multimedia campaign was started to increase the knowledge in the Netherlands of the new tax laws that will influence everybody's life as from the first of January 1990. A small brochure was inserted in all TV guides during one week. Small newspaper ads were announcing this brochure for the next week tv magazine. During that week special television spots were pointing out the new tax laws for next year and that useful information could be found in this weeks televison magazine. This offered the opportunity for the researchers of the group of publishers of tv-guides, the media buying company Media Matters, and AGB-Intomart to use this multi media campaign as a real-life experiment. The purpose was to test if synergy between the three different media types occurred and if there were any multimedia effects on the main goals of the campaign: to increase the intensity of reading of the brochure and to increase the knowledge of the relevant target group on some crucial aspects of the new tax laws. The research was carried out during two weeks by means of 8 daily telephone interviewing waves of between 125 and 170 individuals each. In total 1166 individuals were interviewed. The analyses were carried out with help of multiple regression techniques to show the different influences and interactions from a number of relevant variables on the selected dependent variables: reading intensity of the brochure and level of knowledge on the new tax laws.