The ethics of SEO are often debated. It is a hot button topic that quickly turns into a flame-war whenever it is brought up. So what are my opinions on SEO ethics? I'm glad you asked. Take my definition with as many grains of salt as you feel are needed. 🙂
There are different ways of defining the term "ethical", but the following definition will suffice for my purposes.
According to dictionary.com, ethical means "Being in accordance with the accepted principles of right and wrong that govern the conduct of a profession"
There is currently a thread at SEW at http://forums.searchenginewatch.com/showthread.php?t=4246, which discusses an article written by Alan Perkins at http://www.silverdisc.co.uk/articles/ethical-seo/. I actually find that article to be somewhat overblown, attempting to turn a simple concept into a high-level paper. Frankly, I believe the paper could have been culled down into one paragraph, that expands upon one sentence in the paper - SEO practitioners may behave ethically (or what they believe is ethically) towards their clients.
As far as I am concerned, most techniques used (black hat, white hat, gray hat) are simply techniques - and no amount of moral judgement can be placed upon the use of those techniques.* I mean, really, can you say that keyword stuffing is morally wrong? Or hidden text? There are no morals involved in those techniques. I personally tend to rely upon white hat techniques, with a bit of gray mixed in for some occasional color, but I don't believe that makes my style of SEO either ethical or non-ethical. So where do ethics come into play? It comes into play in your communication with your clients. If you are optimizing a client's site, you should be upfront with the client about the techniques you will be using. You should explain the differences between the techniques (white hat, black hat, gray hat), and the consequences (both good and bad) of using those techniques. The client should be made fully aware of his choices, and the consequences of those choices. Once the client understands, he or she can communicate to you which hat he wants his site to wear. You then agree to abide by that choice, or let him know that you cannot perform the work based on his decision. (I recommend making sure the written contract clearly indicates the choices made).
So, there's my paragraph on ethical SEO. Simple, right? Still not sure what I am saying? Ok, one more paragraph then...Ethical SEO is giving your client the full facts and allowing the client to decide which style of SEO techniques will be used for his site. If your style of SEO meshes with his choice, then you and your client can come to an agreement that is ethically sound. If you only SEO your own sites, then ethics don't come into play at all. It is strictly your choice to decide what risks you are willing to take with your own sites. Play by the search engines rules or not - it is entirely up to you. No written or verbal agreement has been made between you and the search engines requiring you to adhere to the rules that the search engines want you to follow. This entitles you to bend or break the rules as you see fit. It also entitles the search engines to rank your site well, rank your site poorly, or ban your site completely. No ethics involved - no moral judgements to be made. You make your choice and you will then have to live with the consequences of your choice - good or bad - without placing blame on anyone but yourself for doing so.
* I can only think of one technique that might break the rule of no moral judgement being placed upon it - that of falsely leading a user to believe a page is about one thing (kids toys, for example) when it is really about another (p0rn, for example). Since this is essentially fraud, then placing a moral judgment upon the use of this technique is justified.