Black Hat SEO: which practices will earn you a manual penalty?

A couple of weeks ago we published an article covering 12 high profile websites that have been hit with a Google penalty. 
Not all of these companies were in anyway directly to blame. For many it was a lack of education around SEO best practice. Or in some cases an errant SEO consultant earned them the punishment.
In order to elucidate further on the behaviour that will lead to a penalty, let’s take a look at the ‘black hat SEO’ practices.
What is Black Hat SEO?
Any on-page or off-page practice that intends to falsely manipulate a website’s search position. There are many ways a website can do this, all of which are bad for your site, bad for search engines and ultimately bad for the user.
Don’t do any of the following…
Automatically generated content
Anything that looks like it was written by a piece of software is bad for the reader, as the language will be unnatural, nonsensical and stuffed full of keywords.
Even before a penalty is issued, chances are visitors will have already sussed you out and your bounce rate is poor.
Cloaking and irrelevant redirects
Cloaking occurs when different content is served on a website than what a visitor expected to see when they clicked through from search.
You can should also be careful when using 301 redirects that you’re sending visitors to a page with similar content.
Doorway pages
These are webpages used for spamming a search engine by creating multiple pages for specific high-value phrases but end up just sending visitors to the same destination.
Hidden text and links
Hiding text or links can manipulate search rankings, and lead to a ban. There are a number of different ways to hide text on a webpage… you can simply use white text on a white background, use CSS to position text off screen or behind an image, set font size to zero, or hide a link in single character.Like a full stop at the end of a paragraph.
Don’t go looking for it, it’s not there. It was tempting though.

Keyword stuffing
You should use keywords appropriately and in the proper context of the article. Although the value of keywords is diminishing over the years, you should still make sure the title tag, first paragraph and meta description all include your specific keyword. However if your keyword density is too high, this can be a red flag.
Link schemes
Any kind of scheme where links are bought and sold is frowned upon, however money doesn’t necessarily have to change hands. It can be any kind of trade.
Be aware of anyone asking to swap links, particularly if both sites operate in completely different niches. Also stay away from any automated software that creates links to your site.
If you have guest bloggers on your site, it’s good idea to automatically Nofollow any links in their blog signature, as this can be seen as a ‘link trade’.
All sponsored content should also have Nofollow enabled.
Bloggers have also been warned to Nofollow any links to any websites who exchanged a product or service for a review.
Scraping
If you take articles from a site and republish them without permission you will cause all manner of duplicate content issues, and bring down the wrath of Google.
Unnatural link promotion
Much like the link schemes above, this is any kind of trade where one site promises to include links to another in exchange for content or some other promotion. This is particularly noticeable if the links appear to be irrelevant to the content.
User Generated Content (UGC) spam
Comment sections in your website can be a haven for webspammers, so make sure you automatically Nofollow all links that may appear. You should also regularly clean up your comment sections for anything that doesn’t genuinely contribute to the conversation.
Source: ClickZ
Link: Black Hat SEO: which practices will earn you a manual penalty?