Research shows that many companies that target the advertising that can not be achieved if only by doing that advertising alone. For example, it is not unreasonable to set a goal "to convince us that the target market, our products are the best" if it has been clear to them that there are other products better. You can not blame you if the advertising agency that goal can not be achieved.
The first step is to decide a reasonable target advertising. Question to ask is: Is it possible to achieve a target simply by using advertising alone? If the answer is yes, then it is a marketing target. If the answer is no, then it is not a target for advertising.