This article is a response to calls for new research methods in the study of political marketing. We submit that the mixed method approach to studying how political parties use opinion research and political communication is underused. More specifically we believe that campaign spending data, which are commonly analyzed in electoral studies, can become a significant source of information for the study of political marketing. We summarize the availability of electoral expenditure data in 13 established democracies before using a mixed method design to study political marketing management in Canada. We seek to validate quantitative data about marketing spending activity by administering semi-structured interviews with practitioners who held senior campaign positions in major political parties. Our preliminary look at campaign finance through a political marketing scholarship lens reveals the strengths of drawing insights from such data but also some limitations. We conclude that, as other research has posited, Canadian political parties focus more on advertising in their approach to campaigning. More broadly, we propose that students of political marketing should balance proprietary interviews with transparent, standardized, replicable and objective sources of information such as campaign spending data, and vice-versa. Copyright © 2013 John Wiley & Sons, Ltd.