@Julia Fair I usually just start the conversation with... I have a house in the area (or are looking at some) and curious what kind of luck are having finding good applicants, if they expect to get the amount they want, how long it usually takes them to get it rented, etc. But find ways to add value to them too. I like to share my experiences with different types of listings... yard signs, facebook posts, craigslist, Zillow, etc. And be helpful! I had a conversation with one lady who just had a couple of properties and no experience listing her properties online, so I talked her through pros/cons of Zillow, craigstlist, etc and even sent her an email with links, etc. She was very thankful and that was enough for me. It's good to do it just to be helpful, but it often comes back to you at some point too. Call it the "universe," karma, or whatever you like. :)
I called one for-rent sign and told them about some applicants that looked good to me but I had just rented to different applicant. The landlord was extremely appreciative. (Of course I didn't share the details of the applicant - I just asked if I could give them the landlord's number.)
But anyway... you never know where a conversation like that might go... they might be interested in selling, might have other properties, will remember you when they do want eventually want to sell, might refer applicants your way that aren't a good fit for them, etc etc etc.