Ukrainian Marketing Forum is an annual marketing conference that takes place in Kiev. But it often happens that marketing specialists believe in a cult of some academic knowledge they got during the studying in university and don’t want to study something new. We had to make them want to attend our event. We had to make them realize their knowledge is already out of date. In order to demonstrate this, we took P. Kotler’s cult marketing book and spores of mold, placed them together in a city-light panel and let time show off its strength. After a month of tests, failed attempts and disappointments, we found a solution. Our mold grew. Every day, it spread more. And more. The book began to look older. And our message sounded more and more clear: knowledge gets dated, come for something fresh We earned more than 40 publications in local and international media with an overall audience more than 73 000 000. More than 22 000 people saw Mold video case. We reached the Facebook audience of 460 000 people. Ukrainian Marketing Forum sold 31% more tickets than the previous year. And we made all these results with the only one city-light. Maybe, the only case in history when a mold had taken more attention was the discovery of penicillin by Sir Alexander Fleming. And the most important, our city-light started a long-going discussion among marketing specialists on the topic of marketing education.