A logo is form of identity and may also serve as sub-conscience navigational aid for users by providing them with a sense of location that allows them to confirm where they are –have I left the site.
The logo also serves as a reinforcement of the quality of information that may be found on the page this is a reputable organization and the information is likely to be truthful.
A logo can also be used as a navigational aid that allows a user to return to the Home page- I can go back to the HOME if I get lost.
Links that leads to dead ends (the dreaded “error 404. The page cannot be displayed”) are a consequences of poor web page maintained, a concept that Nielsen refers to as linkrot.