Do not try and make all of them say something meaningful/informative to the player. If every NPC pops out with some remark like "I hope you're taking anitdotes if you're going into the woods" you quickly run out of things to say, and it sounds ridiculous anyway. It could be something that reveals a bit about relationships in that town e.g. "If you're thinking of buying anything from that no-good, cheating, underhand creep at the Acme Wizard Shop - don't! That's all I can say - don't!" e.g. "I was just asking my friend here about how to make good bait for fishing. You wouldn't happen to know would you?"
People will possibly want to pass on bits of news, even if it's something known to the player. It can be "Hey, have you heard that Duke Snodkins was assassinated last week? They say that 4 vagabonds (tha's our heroes, btw) did it. Can you believe it?" It doesn't have to be relevant to the story. "The miller over at Farnhackem has managed to break the sails on his windmill. I always said he was useless at maintenance. Now we're going to have to go all the way to Uppingham. I'm so mad I could throttle him."
People could be having conversations between themselves (they don't turn to the player) and if you want a second page, they could turn and tell the player not to eavesdrop on private conversations.