Have you pondered How has private and charitable enterprises experimented on the General Population. To answer this question the experiment has to be defined first. Is advertising on the biggest media conduit - the television, experimental. Is this question you proposed experimental? How is an experiment defined is important, however the purpose is more important?
Experiments are used to test theories.
independent variable (what you change)
dependent variable (what you're measuring)
control group (what you keep the same)
hypothesis (what you think is going to happen)
& your results
Are the affect of advertising measured by purchases and donations? Are those late night time slots chosen because they are less expensive or because of a target market and human behavior?
There is nothing wrong with experimenting since almost everything we do is an experiment of some sort. It is the purpose that should be questioned and if that information of/from the governmental experiments are made available. Check out FRED at http://research.stlouisfed.org/fred2 for some results to some experiments by our Government. I use that as a resource of hubs all the time. Plus, businesses of many kinds do as well.