I discuss this in the post: Nielsen like surveys work when there are a small number of things people can be watching/readings/listening to. Der Spiegel may or m

I discuss this in the post: Nielsen like surveys work when there are a small number of things people can be watching/readings/listening to. Der Spiegel may or may not be big enough for this, depending on how many people are in your panel, but a panel big enough to get good coverage across smaller sights is not practical.