How exactly do I trigger rewards for NPC's "gratitude"?

[KewlCrayon 0]

I think you gotta help out the STALKERs when you get a Stalker Network message. I think I got one for saving someone after a blowout, one guy got stuck and got KO'ed and I saved him, then when I went to bar I had a "I heard someone left something for me" (or whatever it is) message in the menu.