There are different things at different steps. Before a campaign is completed, there is pre-testing done on several concepts. When you hire an ad agency, typically they'll present a minimum of three concepts. Those concepts are tested in the target population to ensure that the messages resonate with them. That's one safeguard.
At the end of the campaign, as part of the evaluation process, if they're large campaigns where the media exceeds a million dollars, they're automatically subjected to an evaluation process. This includes the testing of the audience—whether or not they remember seeing the ad, whether they can recall the major messages.
In addition to that, other types of measurements are done. Typically, an ad campaign will have a call to action, so in the message it will say call this 1-800 number, visit a website, take a particular social action, and there are ways to measure that. We'll measure how many hits there were on the website, or how many calls there were to the 1-800 number. For the home renovation tax credit, one of the results that was put forward was the number of people who actually claimed the home renovation tax credit. So there are different measures like that.