Jeffrey - The following is part of letter #1 in my set entitled "Why home buyers need their own agent."

"So what can a buyers' agent do for you that you can't do on your own?

               Save you both money and time, that's what." 

Another letter explains that the listing agent works for the seller - his or her job is to get the best price and terms for the seller.  The buyers agent works for the buyer - to get him or her the best price and terms. 

Try getting those points into your presentation. 

Also, consider waiting until after you've shown one home to ask them to sign a buyer representation agreement. Back when I was an agent I picked up a LOT of buyers because other agents wouldn't show them a house without it. So give them a little time to get acquainted and learn what you're going to do for them. 

THEN ask them to sign before you spend more time searching for their perfect home.