Google updated its algorithm last week and in search engine marketing terms it doesn't get much more exciting than that.

Called "Jagger", because all new software needs a feline code name to be cool these days, it is the most radical change at Google for months.

Lives are quite literally ruined when Google changes its algorithm as page rankings fly out of the window and previously booming online business get thrown into the internet wastelands of obscurity.

The algorithm is essentially the formula by which Google orders sites for relevance to any given search term. Their goal is to have the most relevant sites at the top and to keep the spammers' sites at the bottom.

Of course Google gave us no warning. Experts in Search Engine Optimisation (SEO) started to notice the sea change and in blogs and forums around the Net the whispering chatter erupted into mass SEO hysteria.

The Google update swept around the world as Google's international data centres were updated in turn, it smashed into the shores of Google.co.uk early Friday morning.

Google's absolute secrecy about everything to do with 'The Algorithm' is understandable. If you caught sight of it, ten minutes later you'd be the richest man in the world.

There is one spy inside Google we all know as " GoogleGuy", who leaks the SEO world information. His real name is unknown, but he has presented enough evidence in SEO forums to prove he's genuinely a Google employee.

Some suspect that GoogleGuy is actually a double agent and is feeding us what Google wants us to know. Unfortunately, many people claim to be GoogleGuy but are just pretenders.

The real GoogleGuy can be identified by the accuracy of his predictions. He has confirmed that "Jagger" is just the start of a big push at Google to defeat the spammers and we can expect more ranking flux in the future.

But one man's spam is another man's meat and to label a website as junk can quite literally take the food off its owner's table. You can officially complain to Google by filling in their feedback form on-line, but don't expect a reply anytime soon.

Matt Cutts, director of search quality at Google, who I suspect is "GoogleGuy", tells us on his blog why some legitimate sites might have got the bullet and how to fix and resubmit them.

But the SEO world is screaming at him for pulling the rug from under what is now a multi-million pound industry. He has promised to give out "weather reports" in the future to help search marketeers survive future storms.

Of course where there are losers there must always be winners.

Some webmasters are delighted that their sites have jumped up the rankings. Many of my customer sites now have vastly improved page rankings, for which I will be taking all the credit of course.

Chris is managing director of internet consultancy WebXpress. This and other unedited articles can be found at www.webxpress.com