Google has announced (11/03/2011 08:19:00 AM) a major change to its freshness algo, which they say will effect 35% of search engine traffic. The freshness algo has been pointed out as a method of SEO in SEO and Headline Chasing.

One way to understand this is to consider for example the term "Cain's 999 plan analyses." Lets now say it gets discussed in a political debate and Google sees a surge of traffic for that term. This could trigger a "QDF" (Query Deserves Freshness) reaction to direct the spiders to do data mining for new content related to that term. Google both checks that is current listings are up to date and if it discovers a link on DRUDGE REPORT it quickly gets that listing into the search results.

This does not mean the end of evergreen content. Even for the terms which trigger a Query Deserves Freshness. local businesses have been showing up in search results and that does not means an end to sites that do national or international SEO. It does mean that it is far more important that you develop google trust so that information you post can get freshness benefits.