The concept of Reciprocity obligates us to repay others for what we have received from them. The norm drives us toward fairness and equity in our normal interactions.
Studies have shown that the small gift of a Coca-Cola increased the likelihood of someone buying raffle tickets. Even if there was a time delay, and even if there was no mention of the gift. Plus, it was irrespective of how much the salesperson was liked. When we help others it creates a social obligation for them to help us.
A manager who allows someone to leave early or get help, will owe them help on a project or do something.
When dealing with a customer service agent, and they start out friendly – pay a compliment or explain that you are really satisfied by the level of service offered so far or say that you would like to be transferred to the manager after to talk about your experience when done – before getting to the big problem/favor.
What “thing of perceived value” can you give your prospects – even before they become customers? Coffee and water don’t count anymore. Maybe it’s a binder to help keep the home listings straight. Maybe a strategy for taking notes to remember what they have seen.
Could give the kids a toy or project to play with while you talk – that they get to take with them.
If you are a Realtor, it could even be “pre-viewing” the properties to make custom videos showing their likes and dislikes.