ALPHAX states: Wrong. Spam and POV hagiographies are banned, *regardless* of who posts them.
Alphax makes the common mistake of confusing the "submission" with the "submitter". All public relations workers are not welcome to edit in Wikipedia, regardless of the quality of their writing, or even whether independent non-paid editors in good standing have personally vetted the content before it's posted.
See [[Arch Coal]] again, if you're confused.