Google are continually improving their search algorithm to give their users the best search results for their needs.
The most recent update affects about 35% of all searches and is focused on identifying searches that require fresh and current information. The new algorithm identifies the currency requirements of a search term. For example if you are searching for a recent news event, you will want the most recent report, not one days old. In this case recent reports are given greater relevance in the Google search index.
What this means for us is that currency is now a very relevant factor when thinking about your search marketing strategies.