Very simply, when advertising gives misleading info, excludes possible harmful side effects, or it is immoral, or if advertising goes against the basic principals: Decency, Honesty, Social Responsibility, Truthful presentation, Avoidance of Harm , and positive Environmental behavior, the, ADVERTISING HAS BECOME UNETHICAL. Have a good day. Thanks.
In 1997, the Pontifical Council for Social Communications released a communiqué on Ethics in Advertising, available at http://www.vatican.va/roman_curia/pontifical_councils/pccs/documents/rc_pc_pccs_doc_22021997_ethics-in-ad_en.html.
In its communiqué, the Pontifical Council drew attention to economic, political, cultural, and moral and religious benefits and harms from advertising. Vitally, it placed emphasis on three moral and ethical principles: (i) truthfulness, (ii) the dignity of the human person, and (iii) social responsibility.
The concept, process, and application of social marketing, which develops activities aimed at changing or maintaining people's behaviors for the benefit of individuals and society as a whole, may be of interest too. The Future of Social Marketing, available at https://www.researchgate.net/publication/239823666_The_Future_of_Social_Marketing, elucidates further.
Ethics in advertising relate to the impact of advertising activities on the individual, the company, the business community, and the society as a whole. All communication involves three elements: (a) the author(s) who originates the communication, (b) the medium that carries the communication, and (c) the audience who receives the communication. Because advertising is a form of communication, it involves these three elements, and the various ethical problems raised by the fact that it is a form of communication can be organised around them. If advertising seeks to move people to do evil deeds that are self-destructive and destructive of authentic community, it is not ethical at all.The moral issues raised by advertising are complex and involve several still unsolved problems.
Promoting a product or service with false claims and indirectly hurting the image of competing product without any factual basis are some examples I could think of regarding unethical advertising.
One should not forget that ethical thoughts are always depending on culture. In my country, Austria, we have a voluntary self-restriction system, called "Werberat". If you are interested in this codex, have a look at http://www.werberat.at/show_4267.aspx (only in German avaiable, but babbelfish will do...). Werberat is part of the International advertising standards alliance - this page is in English: http://www.easa-alliance.org/
Ethical advertising associated with such measurements, such as justice and truth, which enable marketers to successfully implement marketing strategies to gain customer confidence and goodwill. please find some materials: Ethical advertising practices and its impact on the societyhttps://www.ukessays.com/.../ethical-advertising-practices-impact-on-the-society-mark;www.vatican.va/roman_curia/.../rc_pc_pccs_doc_22021997_ethics-in-ad_en.html;www.abmn.com.br/codigodeetica/Artigos/?id=25
Whenever advertising is untruthful and deceptive, offensive and in bad taste(with regards to unnecessary use of sexual appeals in advertising), encouraging materialism and stereotyping in ads. Also when ads are targeting gullible/ naive audiences are some of the cases which can come under the preview of unethical advertising