The close outcome of the Italian general elections of 2006 highlights the crucial role of floating voters, switching from one coalition to its opponent. Using survey data, the paper studies the relation between the degree of political interest and knowledge of individual voters and their propensity to switch between competing coalitions in subsequent elections. Two rival hypotheses are proposed. The first, dubbed the "electoral market", states that most vote change happens among the most interested and informed. On the contrary, the rival hypothesis of the "electoral bazaar" envisages a scenario where floating voters are mostly among the least politically involved. The results of the analysis show a marked difference between patterns in the First and the Second Republic.