Campaigns have wasted millions of dollars in failing to understand what it takes to guard against the preemption of spots -- that is, to guarantee that spots run.

Most stations utilize two classes of time: non-preemptible (or fixed) and preemptible.

Because of an increased awareness to the potential for saving money in the buying process (in part because of LUC Media's political success), many media buyers attempt to place the buy at the lower, preemptible rate.

Then, as demand increases, stations tell buyers that they should pay "fixed" (non-preemptible) rates in order to clear, or worse. To make their point, the stations simply preempt many of the spots in a buy.

At that point, many firms generally pay the higher (often much higher) fixed rates, believing that they are now "invulnerable" to preemption. They could not be more wrong.

For more information, take a look at "The Preemption Myth."