You trade with them and keep them safe/well-fed. Villagers have to gossip, too, so don't let them spread out and don't isolate them. They can't gossip if they can't reach each other. There are a handful of different gossip events (some good, some bad), so it can take some time to spread the word about your good deeds.
Successfully defending a village from a raid will drastically reduce prices. You can make a lot more profit if you stockpile the resources they demand and then feed them those resources after a raid victory.