I just found an article by Anne Krogstad analysing the way the Norwegian politician Kristin Halvorsen used her blog and other web-based media, such as online discussions with citizens, in the election campaign in 2005. One of Krogstad’s conclusions is that the blog seemed to work very well over “the long campaign”, but that in the more intense final stages of the campaign traditional media were used more heavily and seemed more successful. She asks whether this might be generally the case in the success rate of online, participatory campaign strategies.

Krogstad, Anne. “En bok, en blogg og en blondine: Personlig politisk lederskap i nye medier.” Sosiologisk Tidsskrift. 15(3):195−225, 2007.