In addition to people doing business with people they Know, Like, and Trust. They also seek information and advice from people they know, like, and trust. This is done many times even though the sought after information and advice is foreign to that person.
Also, people are alway moved emotionally although their action may be totally illogical.
Imagine if the brightness (wattage) and type was stamped on our heads like light bulbs. That surely would make it a lot simpler to determine who could shed light, and how much on a given subject. Very often people will seek advice from people that are intelligent and versed in a particular field or subject, on a totally unrelated topic and cherish the response.
The reason for this is they seek information based on emotional attachement rather than a logical decision.