QDF is a term used to describe the thought process behind Google’s results for certain search queries’ “deserving” of fresh and regularly updated content.
QDF is Google’s way of ensuring that its users get the most up to date results for certain search queries such as a breaking news event, a major new product launch a topic that always seems to be in the news or a famous celebrity who’s recently been in the news.
In all the QDF results above, Google has tailored its algorithm to serve not only traditional search results but also News, Video, images, and more recently, in the Gaza example, Twitter search results!
In one of his weekly White Board Fridays, Rand Fishkin described QDF in Layman’s terms and gave a great example of how to leverage it for SEO for a brand new product launch (the launch of Dell Adamo is the example he gives). Enjoy!