Kender, not everybody thinks rationally. Sometimes, the heart rules the head. When the aggregate country scores become close, it will get competitive and people will start to do funny things.
I remember one particular online game at http://www.clickclickclick.com/default.asp, in which you support your country by making a click. They have now introduced captcha verification, to make cheating harder. But at the beginning, I remember reading in forums and blogs where people were telling their friends to go to the site to cast a vote for their country. Yes, it was very successful in the sense that it generated a lot of nationalism and interest. But "clever" people started to cheat with Javascript and stuff. In the end, the results didn't mean anything.