The sharing-option "wiki-mode" allows everyone to add additional nodes to the "trail", extending the option "public-mode", which only allows everyone to add additional comments.
WikiMarks on wiki pages have the benefit, that their existence can be signalled to the reader on the underlying wiki page directly by the annotation authors; in this case [Meatball:WikiMark] points to a TimeStamped WikiTrail annotation to this page. Its name/link is [WikiTrail:DiigoTrailfireWikiCollaboration]. There is also a Diigo group [Diigo:DiigoTrailfireWikiCollaboration], where you are invited to join.
Using WikiMarks on wiki pages produces the following benefits:
Funny note: WikiMark is not (yet) a nickname for MarkDilley, who is the creator of the WikiIndex, a commented catalogue on Wikis in the form of a Wiki. :-) -- FridemarPache