We think we are not paying attention as advertisements bombard us throughout the day and night. Our mind wanders, we go to the kitchen or we channel surf. But while we are supposedly not listening, most of the time we are being subjected to ads that are not telling "the truth and nothing but the truth". They hedge a little. We can learn to listen to the claims and see the flaws.
I need to remind you that legally the advertisers can get away with this because of the language of the claim. So in order to find the flaws we are going to examine the language and look at the logic that keeps the ad on the air.