When optimizing a website there are practices considered to be acceptable by search engines and also practices that are frowned upon. Then there are the ones that fall into a grey area. For most search engines, the goal is to organize information on the internet and deliver relevant results to users. They use advanced algorithms to accomplish this and SEO is all about configuring a site to be found and ranked well. The practices that are manipulative and promote a poor user experience in search are known as black hat SEO and those that promote a healthy site are known as white hat.
Disclaimer: There is not really a central location or authority on what is deemed acceptable or unacceptable SEO. Google does have its Webmaster Guidelines1 to help website owners understand what the company feels are deceptive practices and what are not. In general tactics that attempt to deceive web users and manipulate rankings in an effort to spam the internet are frowned upon by search engines. For example getting content that has no real value to rank well would be considered spamming.
White Hat SEO
There are many different viewpoints and definitions2 for white hat SEO but in general it is the practice of using methods to optimize a website for search that also enhance the user experience. Tactics like getting earned backlinks, developing well written and researched content, and maintaining best practices for web page architecture3 are examples of white hat SEO. Making a website be in the best position to be found in search while enhancing the user experience at the same time is considered white hat.
For instance writing blog posts that people want to link to is considered white hat. Website owners that post videos or collaborate with other site owners for links back to their website are practicing white hat. On-site SEO like making sure it is accessible by search engines, having structured data, and making sure pages load quickly are among other white hat strategies.
Grey Hat SEO
Like many other things in this world, it is hard to say that there are definitely practices in SEO that are acceptable and definitely ones that is not. Grey hat SEO is a term coined to describe those practices that are not blatantly deceptive or underhanded but are heading in that direction. The phrase could also be used to describe strategies where it is not very clear whether or not it is good or bad. For example submitting articles that contain links to your site to hundreds of blog sites where you have accounts could be considered grey hat if the content were helpful to users in some way.
Much of this also has to do with perspective and there are many schools of thought when it comes to SEO. Some people for example think any form of manual link building is manipulative whereas others feel like as long as those links are helpful (such as the citations in this post), they are acceptable.
These are practices that are outright deceptive and create a poor user experience as a result. It has become much harder to use some of the more well-known practices. Some common examples of popular tactics that do not work anymore include hiding keywords irrelevant to website content by changing their color, stuffing tons of keywords into the keyword meta-tag, buying links from link exchange sites, cloaking or sneaky redirects among many other tactics. View our breakdown of Saul’s website onpage SEO4.
Using automated software to build links is another popular black hat tactic. Bots that crawl the web will either find and submit comments with links on blogs or forums. They may also be programmed to create profiles where links can be placed. A more sinister practice is to inject “host” sites with thousands of links that they cannot necessarily see but that are found by search engines.