I'm curious about whether political parties pay survey companies for public opinion data. I could imagine, for example, the American parties having a consultancy relationship with Gallup or something. On the other hand, perhaps these activities are all carried out by think tanks, who do the work and transfer the information to parties, but maintain an degree of independence.
In general, I am trying to get a sense of the size of the market for political opinion data. Preferably, I'd like to understand that market in Canada, but I imagine that far more information is available for the United states.
Do you know examples of companies selling political opinion data? Can you cite examples that would be indicative of the size of this market?