Great advice.  You don't need to be paranoid about the possibility of being attacked but you do need to be ever aware.   A realtor in the Bay Area of Calif. was raped and almost murdered.   The suspect was apprehended and when questioned as to why he attacked a real estate agent, he told the police that a fellow inmate (he had just been released from prison) told him real estate agents were easy targets because they ususally had money, a car and were alone.   It appears the word is out there so you need to be prepared.  In addition to the advice given, let the prospective  buyer enter the residence first, never put yourself in a position where you are boxed in.   Have an avenue of escape.  Have the prospective buyer meet you at your office not at the residence, especially if it is vacant.  Try to go in separate cars.  Always have a fully charged cell phone with you with the local police number on speed dial.  By the way there is a  new product out called the Agents 911 that plugs into an outlet in the house and the agent wears a pendant or a bracelet.  If there is trouble and the agent needs help she can activate the system and a 9ll operator is made aware of her need for assistance.  

In addition, I would always have a self defense product with me.   It still takes time for the police to arrive and you need to be able to protect yourself/or escape from a dangerous situation.   A pepper spray pen or a cell phone stun gun would be good choices.   They look like a pen or a cell phone so they would not be offensive to a legitmate buyer but would be at the ready in the event the buyer turned out to be a predator.   At least an agent should have an electronic whistle.   You must be mentally and physically prepared to defend yourself and a good way to do this is to think about the possible vulnerable situations you might find yourself in.   Then, you must fomulate a plan to escape the situation or avoid it.  If you play the scenerio over and over in your mind, should it become a reality you will react automatically and not freeze or panic.  

I have several good friends who are realtors and I have a law enforcement background so I know the dangers and the remedies.  It is a sad thing that we have to live like we are prey animals in the jungle but there are predators out there waiting to take advantage.   Take their element of surprise away by being prepared.   Be safe, not sorry.    http://www.peppersprayetc.com