If you ask Marketo to pull Anonymous = True leads, it will only give you the count for the Anonymous leads - people who never provided an email address, so all Marketo knows is they were on the site because they were assigned a cookie and Marketo ID #.
So in this case, the Company Web Report will show the count of Anonymous leads that are associated with a Company IP/reverse lookup. Keep in mind you'll have a bunch of Comcast or ATT users.
Thanks josh, that helps.
Related question........Is there a way to tell which leads converted from Anonymous to known amd the dates they converted? I thought I might be able to create a smart list and that there would be some type of filter that was "converted from anonymous to known", but there is nothing there like that.