There are ways to use the community as the unit of analysis even if you can’t vary the treatment within a community. There are also ways even to vary exposure of mass communication, ads or PSAs, by the channels they run in at all times of day ... So even with mass communications strategies that you might think can’t be varied, they can be varied. For the most part they are not. So we are spending all of this money to support campaigns and the incremental knowledge gained about effectiveness is very small.