Google is constantly tweaking its PageRank system, and it is important to continually optimize your site so that each time they update, you grow or keep your rank.
Here is what Google says about their PageRank system:
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 considerably more than the sheer volume of votes, or links a page receives; for example, 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.” Using these and other factors, Google provides its views on pages’ relative importance.
There are some things you can do to help boost your rank, and other things that you should avoid so that you aren’t penalized.
Always avoid posting in short bursts if you can, or even worse, at predictable intervals. Google will think you are a content scraper, or that their is a bot (computer program) at work behind the scenes.
Never write for machines. Writing for machines is when you fill your posts with keywords to the point of being spam. Google hates spam, and while you might get some decent traffic at first, if you aren’t writing for people, you will never make it to the upper echelons.
Try to make sure you keep static links in your sidebar and footer to a minimum. These static links are weighed strongly by Google, and if they are all linking to low quality sites, you can bet Google’s algorithm will start to consider you “low quality”.
The biggest tip I can give though is avoiding duplicate content. Some people don’t even realize they are creating duplicate content, but unfortunately, most blogging platforms publish the full text of your posts in more than one place. The full article might be on the front page, under a category archive page, and on your archives page. Google sees this as three articles in different places with the same content.
There are some things that Google looks for that could work in your favor, and one of the biggest ones is inbound links. The more inbound links, especially quality links with a high Google PageRank, you can get pointing to your site, the bigger the boost you will get to your PageRank. Each link to your site is seen as approval from another site that you have quality content. If the site linking you has a higher rank, it is seen as someone important saying you have quality content, and so Google trusts their assessment.
It is said that Google also tracks things like RSS subscribers, but I am not sure how they would get such data, unless they are looking at how many are subscribing to your site via their Google Reader service. With Google now owning FeedBurner though, I wouldn’t be surprised if this is quickly going to become a more important addition to their ranking system, so promote your RSS feeds.
The last factor that I will mention in this article is how often your blog is clicked from their search results. This is where search engine optimization can play a key factor to boosting your PageRank in the next update. If you learn how to properly optimize your site, thus making people interested in clicking on your article rather than the one below or above you, it might just help you get to that next level.
Google is often seen as this big cloud in which little information is divulged, but through research, and due diligence, you can help Google see your site in a positive light and get that PageRank one step higher.