In case you're thinking this is because all these other websites dropped by article and replaced it with other content I should add that a search on Yahoo.com on the same day still showed 14,300 results for my article.
What's more of these 44 results on Google, more than half consist of listings from the same websites. In other words some sites have the same article duplicated on different pages on their website.
So Google's Internet Content Filter is not used to remove duplicate listings from the preferred websites it chooses to keep in the search results.
On August 28th, 2005 8 weeks after first publication I distributed the article again to a new list of article sites to repeat the process. After 6 weeks the same article had reached a peak of 5,620 results on Google. Less than 2 weeks later the results had fallen to 217.
For me this was dramatic proof that Google's Duplicate Internet Content Filter is active and very effective. If you're wondering if other major search engines have a duplicate content filter I can confirm that Yahoo certainly does. The same article which was once listed on 14,300 sites on Yahoo, has fallen to 344 over the same time period.
From these results it would seem Google takes about 6 to 8 weeks to remove duplicate content using its Duplicate Internet Content Filter.
But the question remaining is just how does Google decide which out of over 16,000 results does it keep and which does it reject ?
