The discussion of any SEO code of ethics is like a discussion on politics or religion: There are more than two sides, all sides are strongly opinionated, and seldom do they choose the same path to the same end. Most search engine optimization (SEO) practitioners understand this code of ethics, but not all practitioners practice safe SEO.
Too many SEO practitioners claim a bias toward surfers, or the search engines, or their clients (all are appropriate in the correct balance), and it is common for the SEO pros to use the “whatever it takes” excuse to bend some of the ethical rules to fit their needs. This does not pass judgment; it simply states the obvious.
Although the industry as a whole hasn’t adopted an official code of ethics, here is a specific code that you can adhere to as a way to respect your clients:
Do not intentionally do harm to a client. Be honest with the client and do not willfully use technologies and methods that are known to cause a website’s removal from a search engine index.
Do not intentionally violate any specifically published and enforced rules of search engines or directories. This also means keeping track of when policies change and checking with the search engine if you’re unsure of whether the method or technology is acceptable.
Protect the user visiting the site. The content must not mislead, no “bait and switch” tactics (where the content does not match the search phrase) should be used, and the content should not be offensive to the targeted visitors.
Do not use the continued violation of copyright, trademark, servicemark, or laws related to spamming as they may exist at the state, federal, or international level.
All pages presented to the search engine must match the visible content of the page.
Don’t steal other people’s work and present it as your own.
Don’t present false qualifications or deliberately lie about your skills. Also, don’t make guarantees or claim special relationships with the search engine.
Treat all clients equally and don’t play favorites.
Don’t make false promises or guarantees. There is no such thing as a guaranteed method of reaching the top of the results page.
Always offer ways for your clients to settle disputes. There will be competition among your clients’ websites. Make sure there’s a way to mediate conflict if it ever comes up.
Protect your clients’ confidentiality and anonymity of your clients with regard to privileged information and any testimonials supplied by your clients.
Work to the best of your ability to honestly increase and retain the rankings of your client sites.
In a nutshell? Don’t be evil. Spammers never win, and winners never spam. What works in the short term won’t work forever, and living in fear of getting caught is no way to run a business.