How large is the Deep Web and how does the content differ from the “surface” Web?
Public information on the Deep Web is thousands of times larger than the commonly defined Surface Web. Deep Web sites tend to be narrower with deeper content than conventional surface sites. Total quality content of the Deep Web is at least 1,000 to 5,000 times greater than that of the Surface Web. Deep Web content is highly relevant to every information need, market and domain. More than half of the Deep Web content resides in topic specific databases. A full 95% of the Deep Web is publicly accessible information – not subject to fees or subscriptions.
