"So paid promoters are required to disclose their compensation?"
Uh, yes:
"Section 17(b) of the Securities Act of 1933 requires that any person that uses the mails to publish, give publicity to, or circulate any publication or communication that describes a security in return for consideration received or to be received directly or indirectly from an issuer, underwriter, or dealer, must fully disclose the type of consideration (i.e. cash, free trading stock, restricted stock, stock options, stock warrants) and the specific amount of the consideration."