That may have been the previous Nielsen measurement, however if you remember, Nielsen signed an agreement with Dish for their viewing information. Every receiver connected to the phone or internet atleast once per week uploads that info to Dish and it is shared with Nielsen for a more specific data point. This will give precise viewing habits, times, dates, number of tvs in house, etc. in addition, the networks do control their commercials wait time(C3, C7, C14, C30, C45 and C60). So with that data, as mentioned, it completely devalued ad space.