Over the years there has been lots of discussion in the SEO community regarding building links to a web site. The debate is particularly heated at the moment, as Google rolls out its "Jagger" upgrade.
Let's start with what we mean by inbound links, also called backlinks. These are links from other sites to your URL, which direct the surfer directly to your site when the link is clicked. The basic premise is that if you have high ranking sites linking to you, then you must yourself be important and have valuable content, and hence you should rank highly. The way in which Google ranks sites is called Pagerank and can be seen as a green line on the Google Toolbar representing ranks 0 to 10. As Google states
PageRank relies on the uniquely democratic nature of the web by using its vast link structure as an indicator of an individual page's value. In essence, Google interprets a link from page A to page B as a vote, by page A, for page B. But, Google looks at more than the sheer volume of votes, or links a page receives; it also analyzes the page that casts the vote. Votes cast by pages that are themselves "important" weigh more heavily and help to make other pages "important."
Important, high-quality sites receive a higher PageRank, which Google remembers each time it conducts a search. Of course, important pages mean nothing to you if they don't match your query. So, Google combines PageRank with sophisticated text-matching techniques to find pages that are both important and relevant to your search. Google goes far beyond the number of times a term appears on a page and examines all aspects of the page's content (and the content of the pages linking to it) to determine if it's a good match for your query.
So, back to the question "Does having inbound links to your site help your site's credibility", and hence visibility when searched. The broad answer to this question is "yes", but with a number of very important caveats which we will cover in the other sections.
OK, so backlinks are basically good, especially from high ranking sites, so how do we get them? The first way, and best way, is by having such great content on your site that all these high-powered sites want to link to you. Downside to this method is that it is slow and takes lots of time and effort on your part. But don't worry, when anyone tries to build a level playing field there are always people out there that will provide work-arounds.
The first one was reciprocal links, whereby you say that you will link to a site if they also link to you. That's stretching the original idea, but it's not too bad because how many of these sort of links are you going to set up? Well, actually, some people have created thousands of such links between sites, maybe not what Google initially intended!
But then, due to the emphasis Google placed on link popularity, the concept of link farms was born. These are sites that link to other sites purely to increase the links to the site. Pay a few dollars and get thousands of links to your site. Too good to be true - you bet. Google hates link farms and sees these links as spam and will actively penalise sites that use such links. So, the first rule of linking is do not use link farms. The second rule is do not use lots of reciprocal links, Google can easily check this and the "Jagger" update that is currently rolling out seems to be particularly focused on penalising sites with lots of reciprocal links. The jury is still out on whether "themed" links will be treated in the same way. "Themed" links are links to sites that are very closely aligned to the same primary topic as your own site. If you think about this, it makes a lot of sense and is much more likely to be based on real content-based linking.
We believe another area Google is focusing on is how quickly your site gains backlinks. If your site is one month old, it is hardly believable for it to gain 100 real backlinks in that time. So, the third rule of linking is to ensure your links build in a realistic way. In all of these ways, Google is trying to ensure fairness and that's why new sites are often held back in the results pages.
Finally, we should mention the sites that will improve your ranking - the Directories. There are many of these, but the most important is DMOZ, also known as the ODP. DMOZ is the Open Directory Project and is the largest, most comprehensive human-edited directory of the Web. It is constructed and maintained by a vast, global community of volunteer editors. It gets the name DMOZ from the acronym for Directory Mozilla, as it is administered by Netscape Communication Corporation. It's Pagerank is 9 and hence a link from DMOZ will help your site. We recommend that everyone visits http://dmoz.org and attempts to get listed, it's free. The Yahoo directory is also important and free for non-commercial sites, but $299 a year for business.
So, in summary, by far the best way of getting links is by having a quality site that other people want to link to. So again, we are back to content. If you provide quality information, over time, more and more sites will link to you, and if they are in the same business sector as you, so much the better.
And now a poem
Written by my partner, reflecting the Jagger update.
Just when you thought it was safe,
To step once more into the water,
Google throws in an undertow,
For doing things you didn’t oughta,
Just when the surfboard is glistening,
And you're ordering champagne,
Google has been quietly listening,
And feels you need more pain,
Those link farms you visited,
Weren't health farms after all
Reciprocal now is the term
For what Big G's doing to you all,
Your trillions of two way linkages
Now millstones to make you stagger,
Your new nightmare shrinkages,
Brought to you today by Jagger,
A strident voice proclaiming links,
Are running quickly out of time,
Under the boardwalk of history,
Lying decimated all down the line,
This will not be the last time,
That your website is torn and frayed,
That Google will paint it black,
Or the devils sympathy card is played,
Just shine a light on your website,
Is it still under your thumb?
Or is it hijacked like flight 505,
By others who would become,
Your link promoting partners,
Who just ask your link return,
And now you owe the reaper,
And your harvest starts to burn,
Simmering in the torrid glare,
Of a Google bent on being cool,
Where everyone should fight fair,
Everyone obey the golden rule,
And slowly and inexorably we move,
Out of shadow and into light,
With every upgrade evening up,
The distance twixt wrong and right,
And every route 66 drives towards,
Eliminating devious spam-like crimes,
And ever inexorably inches forward,
Towards its own stated guidelines.