Susan, CPA, performs compilation services for Dalstar, a nonissuer. The compilation reports issued by Susan disclose lack of independence and are not used by third parties. Susan has accepted a commission from a software company for recommending its products to Dalstar. The commission agreement was disclosed to Dalstar. Susan also refers Dalstar to Thomas, CPA, who is more competent with respect to engagements involving the industry in which Dalstar operates. Thomas performs an audit of Dalstar's financial statements and subsequently remits to Susan a portion of the fee collected. The referral fee agreement was likewise disclosed to Dalstar. Susan accepts the fee. Who, if anyone, has violated the AICPA Code of Professional Conduct?