Herman Cain holding a copy of his autobiography, "This Is Herman Cain!"

Former Godfather's Pizza CEO Herman Cain likes to tout his background as a business man, but one of his ventures could cause him trouble on the trail. A for-profit publishing company owned by Mr. Cain called "Herman Cain T.H.E. New Voice" received over $150,000 in campaign contribution cash.

"Herman Cain T.H.E. New Voice" is a Georgia-based company that sells Mr. Cain's autobiography, “This is Herman Cain! My Journey to the White House,” and a series of books, booklets, and DVD's featuring the candidate. Offerings on the "Herman Cain T.H.E. New Voice" website include "Speak as a Leader," Mr. Cain's book on public speaking, video of Mr. Cain giving an "impactful and humorous" presentation on creating "happy customers" and a pamphlet Mr. Cain wrote on "leadership."

According to Talking Points Memo, Mr. Cain's campaign made four payments to his publishing company for a grand total of $151,779.81.  Payments to Herman Cain T.H.E. New Voice were documented in campaign finance reports Mr. Cain's campaign filed with the Federal Election Commission. The cash was listed as going to "books," "booklets," and "event supplies." One payment was initially documented as including charges for “overnight”, “lodging”, “ground transportation” and "air fare," but the travel costs were removed.

Mr. Cain told Bloomberg Businessweek his campaign paid Herman Cain T.H.E. New Voice for copies of his writings.

“They are buying my books and my pamphlets, ... the campaign is buying them from T.H.E. New Voice,” Mr. Cain said.

Campaign finance experts told both Talking Points Memo and Bloomberg Businessweek they generally advise candidates to work with third party vendors rather than their own companies during campaigns to avoid signs of impropriety. If your business is found to have overcharged your campaign, it can be seen as ripping off donors. Cutting yourself a deal is equivalent to an in-kind campaign contribution.

Mr. Cain's payments to T.H.E. New Voice may raise eyebrows, but it's doubtful he's currently making a killing off of his campaign. So far, according to Talking Points Memo, Mr. Cain has loaned $675,000 of his own cash to his campaign.