An ever increasing number of citizens turn to voting advice applications during election campaigns in order to get a clearer picture of where they politically stand. They do so primarily for comparing their political views on issues with those of political parties and/or individual candidates. Little is known, however, on the impact of the electronically delivered advice on party identification and vote choice. If a voter finds out that he or she is not closest from his or her "usual" party but from another one, does that push this voter to switch party allegiances? Or does the voter remain immune to the advice? Additionally, does a voting advice application have an impact on its user's propensity to turn out? How context-dependent are these effects or non-effects? This paper will empirically examine, in a comparative perspective, these important issues of electoral behaviour applied to the European Parliamentary Elections of 2009. The authors will draw upon a vast data base, generated by the “EU Profiler”, a pan-European voting advice application designed for the EP 2009 elections.