Roman copy in marble of a Greek bronze bust of Aristotle by Lysippus, c. 330 BC.

In Aristotle's Treatise on Rhetoric, he offers the following definition of rhetoric: "The faculty of observing, in any given situation, all available means of persuasion." He continues by defining three key "means" of persuasion: ethos, logos, and pathos.

Logos-based appeals are persuasive messages that find their roots in formalized rules of logic: a thesis supported by arguments supported by evidence. Pathos-based appeals use emotion to move an audience to act or think in a certain way. Ethos-based appeals rely on the character or credibility of the message source to move an audience.

According to Aristotle, an action (or message) is ethical if it does not reduce the speaker's ability to make future ethos-based appeals. In short, if you are doing something that hurts your credibility, Aristotle finds that action to be unethical. In the digital marketing world, the explosion of new tactics for getting your content in front of viewers has resulted in many companies skirting, if not entirely crossing, the ethical line in their marketing activities. Here are three key things some digital marketers do that are unethical:

1. Unethical Search Engine Optimization (SEO) Techniques. Having a website that is on the first page of a search engine's results for certain terms is of significant value. As such, many digital marketing departments have engaged in unethical tactics for increasing the page rank of their digital properties. Some strategies include using hidden content in pages filled with keywords that search engines see but are invisible when viewing the page, link farming to obtain inbound links to your content that are not organically derived, and article spinning, where an article is automatically re-written dozens or hundreds of times using synonyms for the original words and then posted around the Internet on other websites to provide backlinks to the author's site. All of these practices are legal, but are ethically questionable. Before you employ "black hat" SEO tactics like these, consider the following question: If your audience knew you used these techniques to get them to visit your site, would you lose credibility with them?
2. Spam Email Marketing. Not only is spam illegal in many countries, it's also unethical. Sending unsolicited email to millions of addresses may be profitable, but for the vast majority of recipients, it will reduce your company's ability to make future appeals based on your credibility.
3. Paid Likes and Follows. To be sure, your company's social media credibility is enhanced when visitors to your pages see that you are "liked" or "followed" by hundreds or thousands of others. However, companies should be wary when they use marketing services that promise to have your pages liked or followed by hundreds or thousands of users. In almost every case, the accounts that will be following you are nothing more than computer-controlled bots that like and follow all of the accounts who pay for their services. In terms of organic reach, your paid likes and follows will not generate any social contact with your customers or potential customers. Further, consider Aristotle's definition of ethics - would you lose credibility with potential customers if they knew that your thousands of followers were all paid bots? Probably.

Ultimately, digital marketers still engage in these activities because they are (at least marginally) effective. However, the damage the use of these tactics can have on your companies reputation and credibility is considerable. Ultimately, socially responsible companies use ethical digital marketing strategies to connect with customers and maintain relationships while maintaining their own credibility with future potential consumers.