In this paper we analyse the phenomenon of catchy melody in music and marketing environment. We characterise melody as a general concept and also deal with the terminology of the „earworms“ phenomenon. We analyse „earworms“ from the psychological point of view, observe various techniques and strategies in composing catchy tunes and hits. We look at the effect of „earworms“ on a person in a shopping and marketing environment. The empirical part was realised by a questionnaire and investigate general knowledge of the „earworm“ concept, its occurrence frequency and character. We also compare results and answer priori hypotheses. The results are evaluated in charts and graphs.