The respondents to our surveys are not aware of the topic until the moment they click. Usually the best way to do it, to maintain their engagement and to have them answer on several things, is to mix it with other things. It's not necessarily a stand-alone survey where we invite people to take a survey on electoral reform that will be presented on Tuesday. It's more about the reality of just having the randomness that is required for this type of exercise.
There may have been other questions related to other topics on the same survey. It's the best way to ensure that it is truly random and not only the people who want to take the survey on a specific policy issue or something else.