Examine ads from customer perspective.
Like in everything else, mistakes happen in advertising. However, some mistakes result merely from the failure to look at (or listen to) the advertisements from the perspective of the intended audiences.
Taking the time to closely look at the words and images to anticipate how they will be received by consumers is a must. Sometimes businesspeople are so close to the ad or time pressed that problems are not found.
For example, the newspaper ad shown is for a "huge" sale going on at a local car dealer.
Stop... you might pay too much! Unless you shop at our dealership this weekend!
However, this appeal does not match up with the image just below it which indicates prices won't be slashed (see the blue arrow inserted on the ad). Oops.
It's not the end of the world. Maybe not many people noticed it... but those who would were likely interested in the advertisement (a.k.a. car shoppers!). In any case, it could have been caught and corrected prior to publication.