Here are some noteworthy initial findings –

Many SEO analysts believe that Google is filtering sites using a secret filter list. I do not believe this to be true. I’ll explain a little below -

Is Google filtering sites if the search term contains ‘money keywords’?

Since the hardest hit sites are from commercial categories, many SEO analysts believe that Google is filtering sites, which were ranking through search terms containing ‘Money Keywords’ (also called ‘commercial keywords’ or ‘hit list words’). Initial tests conducted by analysts indeed show symptoms that seem to substantiate this theory.

What would be Google’s motive?

If true, why would Google want to do this? The reason that this speculation seems to getting substantial backing is because the timing of the algo change effect coincided with shopping season as well as the forthcoming Google IPO. Analysts believe that Google wants to force commercial sites to now pump in money in their AdWords paid listing program if they wish to cash-in on the December 2003 Christmas season. The free ride seems to be over. Others believe that Google wants to paint their bottom-line a little rosy to impress their future investors.