You mean the talk with random townspeople/villagers? It CAN be useful, albeit slightly, since they sometimes tell you the cities that buy things for a high price (you can just as well assess local prices, I know) and sell stuff cheap (which is usually the more interesting of the information). And you can figure out which Lords are dishonorable (those that execute people for shooting deer in their forest), which might be useful if you want to get the "Raid the caravans"-Quest but forgot which Lords are the evil ones. And other minor stuff like that...
Since there's no way to note down the information in any of the menues however (I think someone once suggested a kind of a notebook where these things would be included automatically which would've been awesome imho), the information is usually lost in time and space.