Advertisements have to include the truth. If your word isn't credible in your advertisment, the customer will not even take the time to try the product. Once you are seen as dishonest, it is hard and sometimes impossible to regain the consumers' trust. Do not make unrealistic claims about what your product can do or will do for the customer.
Cheerios claims to be toasted whole grain oat cereal and Panera Bread is baked fresh in their ovens every day. Those advertising points are the reasons that people choose Cheerios and Panera Bread over other cereals and restaurants. On the flip side, those are also the reasons that other people do not choose to consume these products. Each customer knows the truth about the products and therefore makes an informed choice.
As a consumer, we want the facts so that we can make appropriate choices. Consumers are quick to turn against companies that lie in their advertising. So after viewing the commerical below, I am sure that I will eat green apples all the time. Now what was this company advertising? (wink)