The Next Google Update is Today, Tomorrow and the Next Day!
That’s right. Google is doing an update today, tomorrow, the next day and in fact every day after that!
Google continually updates their rankings of websites and web pages. They only update the visible page rank of a site every 10 - 14 weeks. The visible page rank is the ranking displayed in the Google Toolbar.
PageRank Tip! - If you need to turn on the PageRank option in Firefox, simply click on the Options button in the Google Toolbar, and then check the box for PageRank and hit OK.
So if you make positive improvements in your site today, it could have rapid beneficial impact tomorrow.
You should be more concerned about how often Google Bot is scanning your site and your pages. This is the reason why you should link back to your older articles as well. Links to those older articles in new articles helps Google Bot do an update on those old articles, and possibly give those articles a boost.
