One of the most commonly misunderstood subjects about Google is PageRank. It’s difficult to understand the whys of how Google approaches this, making some facts very secretive and some very public. But, there are some things that we can understand, such as the PageRank as shown in the toolbar.
Toolbar PageRank is a snapshot of real PageRank. The most recent toolbar PageRank update happened just a couple days ago. What the toolbar is now showing is how the PageRank appeard at some point in late December.
How do I know this? Well, because it included PageRank from some links that I added in mid-December, but not some that I added on December 30th and 31st. It’s possible that Google captured the PageRank on Christmas weekend itself, and updated the toolbar on New Year’s weekend.
Why is it important to understand that this is a snapshot? The PageRank you see in the toolbar is old news. The search engine itself updates PageRank on a daily basis, more or less. In fact, it depends on the importance of the site how often it’s updated. If you get a link from a very important site (high PR), you’ll get updated far more quickly than if you get a link from a low PR site. You can test this by adding new links and monitoring your positions before, during, and after.