Search engine optimization is a shifting landscape and what is often totally acceptable to the search engines later becomes totally unacceptable.
Getting links from directories was a classic case of this. Google recommended it publicly. But when tens of thousands of directories sprouted up just to provide webmasters with links they were dubbed Link Farms by Google and using them could lead to penalties where part or all of your site would be removed from their search results.
That means, when you are carrying out SEO work, its vital to use up to date information or you could end up steering your website towards disaster. Again I'll give my How to SEO guide a plug - its completely Black Hat free,
Now you might be picking up that I'm talking kind of funny here. I keep saying my SEO guide is not Black Hat rather than saying its White Hat - I mean the on-Page things you need to do are white hat but the off page can be seen as Gray Hat.
So Google says as a webmaster you shouldn't do anything in order to manipulate your position in the search results. And especially, especially, you shouldn't pay for backlinks from other websites - this is the cardinal sin that will bring down the Google gods upon your site and banish it forever. Or a little while anyway.
But what if I give a product to someone for them to write an online review about it. They will undoubtedly include a link to my website but ultimately I paid them for it with the product. I've breached Google's terms. Trouble is everybody does it.
Or let's say I made a really excellent infographic and offered it around to others for free. If any of them put it on their websites and link to me I'm getting that link because I got in touch with those people and paid them via some well presented content - good infographics don't come cheap.
Again that's exactly the kind of stuff Google is talking about - paying for links. By the letter of Google's law its illegal but it never takes action on this because its how the world works. It's not white hat, it's not outright black hat, it's gray hat.
What Google is really driving at is outright 'cash for a link' schemes. Those ones you usually see offering links from Private Blog Networks - pretend blogs or article websites which in reality just post articles to create links other webmasters have paid to get. You did nothing to deserve those links except hand over some wonga and that's not making the Internet a better place.
In my guide some of the systems I advocate for getting backlinks do probably fall into the Gray Hat category but I would never, ever recommend you simply pay cash to get a backlink. These schemes will catch up with you in the end. The short history of the Internet is littered with schemes that their owners promised were 'completely Google safe' until they, and those that used them, were trashed in some update or other.
But beware you will find many people offering Black Hat services but claiming they are gray hat "because Google hasn't spotted them". Private Blog Network links are a classic example of this gray hat posturing. Google catches up with Private Blog Networks all the time because their filled with so much poor quality and thin content. You may or may not get a penalty but you will have wasted your money.
It's really simple. Just ask yourself, "Am I making the Internet a better place or am I just doing this to get more visitors to my website?" If you are making the Internet richer - because there will be reviews of your products or infographics that help people understand information - then you're fine.
Reaching out to others and making them aware of content that would make their content better is the whole spirit of the Internet and the motivation that will drive up the quality of content across the web so don't be afraid to let others know.
But make sure that's the limit of what you do. If you start saying things like "Oh, and when you link to my website please use the anchor text 'wibbly wobbly'" or whatever and you ask half the webmasters to mark the links 'nofollow' well then you really are trying to manipulate what Google sees.
Black Hat SEO - underhand stuff you do to get higher rankings when your content doesn't really deserve to be above what is already at the top of the search results. Do it at your own risk but don't be surprised if you get thrown out of the search results.
For all on-Page SEO stick strictly to white hat. This is one area Google knows who the guilty party is if you don't. When it comes to off-Page use common sense. If you are making the web a better place then you have nothing to worry about even if you are paying in kind for a link. But it is a straightforward "I'll pay you, you'll give me a link" then you're going to get trouble somewhere down the line.
I'm Tim Hill, a Search Engine Optimization and Online Marketing specialist. I created this site to help others understand that SEO is not a mysterious black art!.
If your a newbie try the Getting Started in SEO page, otherwise feel free to dig around and learn more.