They all seem to belong to the same guy.
They all have the same PO-Box. At least the affiliate pages of all of those sites tell me so. (Not the actual websites, who have NO valid contact address.)
The funny thing: The main idea to check out the PO-Box addresses actually derived from a youtube video by user frimam49 aka Dave J. Castle.
Bryan Dean, his name sounds familiar, but I cannot quite place it. Google search found just the links to the ebooks in question. So who is he? Please anyone tell me!