It is about Google's much talked about page ranking mechanism. And why it does not work too well when it comes to weblogs.
The page ranking mechanism, for those who do not already know it: Google ranks webpages by the number of hyperlinks to that page in the internet. It is not so simple but it works some thing like that. Now, when it comes to weblogs, almost every blogger has a big number of links to his blog in the net. The links come from weblog directories, the blogging tool hosting sites like blogger, retrolinks from other bloggers and many more. A big number of links to an active blogger's page comes from the comments that the person leaves on other blogger's pages, or one's own pages, as it is a practice to put a link to one's blog with each comment. And bloggers generously mention about posts from other bloggers and add links to their page. With all these, in hardly a few months time, a weblog will have hundreds of links to the page on the net. And this means that the page rank will soar, even though you hardly have some 10 to 50 visitors coming in every day. Advantage blogger! ;-)
Added to that, Google gives some extra importance to pages that get updated very frequently. The more frequent you update your pages, Google's crawler comes back more frequently to check your page for new content. To realize that, check Google cache for rediff or any other news site, and check cache for a less updated site, may be your own. You would see yesterday morning's page for rediff but your page in Google cache may be a week old. I presume frequently updated sites find a better page ranking(not sure about this) which again increases a weblog's page rank.
And this is probably why we all bloggers see our pages getting a lot of traffic coming in from Google! ;-)
And here is one interesting case: One of my old posts gives a link to this site, where you can download the game pacman. And if you give a search for 'old pcman game download', my page ranks better than the site I have linked to! Note: plase read the warning given in my post if you plan to download the game.