Freshness

The Google Caffeine update favors recently published or updated content, especially for time-sensitive searches. Highlighting this factor's importance, Google shows the date of a page's last update for certain pages. Google may give newer pages a boost for certain searches.

It is widely believed that website updates, especially content addition, work as a site-wide freshness factor, although Google has recently denied that they use “publishing frequency” in their algorithm.

The significance of edits and changes also matters. Adding or removing entire sections is more significant than switching around the order of a few words or fixing a typo.

The frequency of page updates may play a role too.Although Google prefers fresh content, an older page that's regularly updated may outperform a newer page.