When you build links to your site or a clients site, there are numerous ways to approach it, however it’s worth bearing in mind that all links are not created equal. I’m going to assume here that you know how blog comments and articles are almost worthless these days anyway. So the following points are in regard to how the authority of a link may be calculated. It’s also worth noting that domain authority probably plays as much of an important role in how much power a link has compared to Pagerank, possibly more.
Having the exact term you want to rank for in the anchor of a link is crucial, so whenever possible always make sure the link uses the exact same term that you (should) have at the start of that pages title tag. However, don’t go mad! 10,000 links all pointing to an inner page with an obscure long tail query is going to look highly unnatural.
The first thing to bear in mind here is that the PR you can see from the Google Toolbar is dated, at the time of writing this post, about 7-8 months out of date, so don’t base a decision on the PR you can see, it’s updated “behind the scenes” constantly so what was a PR 5 page could now only be a 2, likewise a PR 0 could actually be a 5 by now. That being said, the actual PR of a page does have a bearing on the weight a link carries, so without getting hung up on it, it is still a consideration, although the only time you can give it much weight, is immediately after an update.
This is where it gets a little grey, as there is not (that I have found anyway) a definitive definition of what domain authority is. I know, this doesn’t make life easy, but bear with me! It’s likely that the authority of a domain is based on other authority and trust of links pointing to it and possibly the age of the site. So for example, this means that a link from an aged .gov site, even if the link is on a PR 0 page, is probably well worth having, provided the page is related and they use your target keyword.
Where the Link is Placed on a Page
It was formally announced by Microsoft that they considered the position a link can be found on a page has a bearing on the weight it carries. The others have not, but testing would indicate that Google have a similar policy. It seems that a link within the main content of a page is most valuable, then the header, sidebar and footer.
OK It’s getting late, so I’m going to end it here for now, but will be adding another post which includes other factors to consider, and due to my nifty related posts plugin, it should appear right below this one as soon as it’s added.