How does a realtor get commission if the house you decide to buy is not his/her listing? Or do they get one at all?

Hello….I’m still on the hunt for a new place to live. I am going to visit some of my choices in the near future and need some advice. I am not just going to one town….but a few smaller towns within fifty miles of a major city. I am probably going to ask one realtor in each town to show me the properties they have in their respective towns. I’ve done all the research, pulled the specs, everything. What I am doing is asking the realtor with the most listings that I like to show me the houses in each particular town.

However, there are still a few listings in each town that are not by the realtor who will be showing them to me. I guess I am concerned that after they agree to schlepp me around, I won’t buy their own listings (or their agency listing) and opt for something else. Does anyone know how this works? Do realtors get something if they sell someone else’s listing——even if it is for a totally different agency?