Most agents' service ends at the closing table. Mine doesn't. I have found contractors, arranged movers, set up utilities and done final walkthroughs for clients who could not be here themselves — and I still hear from people, and answer, years after their sale closes.

A good share of my clients buy and sell from a distance — Ohio, New York, Colorado, Connecticut, Canada. One couple bought their vacation home on a one-week trip and, ten years la...