Here ya go. Shamelessly plagerized from RESPA......

(7) the term "affiliated business arrangement" means an arrangement in which

(A) a person who is in a position to refer business incident to or a part of a real estate settlement service involving a federally related mortgage loan, or an associate of such person, has either an affiliate relationship with or a direct or beneficial ownership interest of more than 1 percent in a provider of settlement services; and

(B) either of such persons directly or indirectly refers such business to that provider or affirmatively influences the selection of that provider; Since the definition of associate is also important to an understanding of affiliated business arrangements, I have also included the definition of the term "associate" from 12 USC 2602(8):

(8) the term "associate" means one who has one or more of the following relationships with a person in a position to refer settlement business:

(A) a spouse, parent, or child of such person;

(B) a corporation or business entity that controls, is controlled by, or is under common control with such person;

(C) an employer, officer, director, partner, franchisor, or franchisee of such person; or

(D) anyone who has an agreement, arrangement, or understanding, with such person, the purpose or substantial effect of which is to enable the person in a position to refer settlement business to benefit financially from the referrals of such business.

Steve,

The definition of ABA is innocent enough and by it's meaning the consumer would benefit from the arrangement through the consolidation of services and the likes. The same can be said for communism. It's truest form is the perfect government to which every citizen benefits and no person is left without. We know how that all turned out.

With that being said, ABAs will sometimes make the title insurer that has them, raise their fees in order to stay profitable while paying a certain legal percentage to an affiliate with the understanding the affiliate will send business to them regularly. Many companies use the ABA to partner and consolidate services for their clients. Many time they are beneficial just in their inherent open lines of communication and faster service.
Where they sometimes go wrong,  Robert has mentioned above is they can be taken avantage of by the referrer. They claim a sense of entitlement since they are referring the business to the title company. This sometimes leads to the referrer asking for thing which would be illegal or against the standards that the title company uses. If one is to adopt an ABA a clear definition and outline should be laid as far as the standards and practices of each affiliate as to never have a situation like Robert's ever arise.
In some markets where there is a title insurer on every street corner an ABA is almost mandatory if that company will have any longetivity or survive at all.

Hope this helps.

George