When Google announces that it is going to make changes to its search engine algorithm — i.e. the formula which decides on the inclusion and ranking of web sites — this is not really a radical change. Google tweaks its algorithm every day.

The main difference is that this time, it is going to affect more sites in a shorter time than normal.

The problem is that there are several sites that are making a business out of a core property of the Google algorithm. Google likes sites that provide original content of interest to readers. Traditionally spammers would put up pages with content scraped (stolen) from other sites and present it as its own.

Google is getting better and better at catching such sites by identifying duplicate content. Google rewards web pages with many links from popular and trust worthy sites. Since spammers cannot expect people to link to their copy and paste web pages, they put up a lot of sites that link to each other. Google is pretty good at finding dubious inter-linkages of this kind.

This is why some sites have specialized in getting people to write new and original content for them. This makes it less likely that the duplication alarms go off, and it is even possible to get people to link to some of these pages. Organized linking takes care of the rest.

The fact that these sites have original content, though, does not mean that it is very good or very useful. You have probably read quite a few of these pages yourself when searching the net. The articles includes a few paragraphs of relevant content, but these paragraphs do not tell you anything new. They are the kind of articles that tell you that if you want to succeed at a job interview it is wise to brush your teeth. It isn’t exactly wrong or irrelevant, but it is news to very few of us.

The problem for Google is that such pages may outrank pages of greater value — pages on web sites that provide more in depth and thought provoking content. And these are the sites Google would like to reward in its latest major algorithm tweak, and they will do so by punishing “content factories” or “content farms”, as well as the more traditional spammer and scraper sites.