This paper will present the results from a comparative study of global political marketing to examine why parties are more or less likely to adopt marketing principles and techniques in their campaigns to win support amongst citizens. It will ask whether there are political structural factors that explain variations in marketing strategies between parties, for example incumbency v opposition status. We also examine whether media structures have an impact, for example, private v public ownership. We address these questions in a comparative study of parties across 14 countries. We find that despite an initial expectation that the political system would have a significant impact, this did not turn out to be the case. Additionally, whilst marketing is used in various forms all over the world, when considering all parties regardless of size, the dominant trend is sales-oriented rather than market-oriented. It remains true that major parties have had notable electoral success with market-orientations, but it is not the case that all major parties become market-oriented and stay so. Rather, parties move back and forth between market and sales orientation and it is here that political system variables such as a new leader, incumbency, time in opposition and internal culture, play a causal role. What determines electoral success and responsiveness to citizens therefore is much less amenable to management by marketing consultants and more determined by the party, its elected leader, and voters. Our findings suggest, therefore, that there is no inevitable shift by parties towards a market-orientation - and the extent to which there are examples of such a shift, it is more due to the preferences of voters and party leaders than due to the duplicity of marketing strategists.