Walk past any apartment complex in Korea on a weekend and you'll see it: two strangers meeting by the lobby, one handing over a boxed monitor or a rice cooker or a barely-used stroller, a quick nod, and they're gone. That's Danggeun Market (당근마켓) — the app English speakers know as Karrot — and it runs the country's enormous secondhand economy. Koreans furnish whole apartments off it, offload things they're done with, and give away what they can't be bothered to sell. For a foreigner setting up a life here, it's the single cheapest way to get a room's worth of furniture. But the etiquette is unwritten and very real, and getting it wrong marks you instantly. Here's how it actually works.

What Karrot Actually Is

Karrot is hyper-local by design. When you sign up it locks you to your neighborhood (동네) using your phone's GPS, and you mostly see listings from people within a few kilometers of you. That's the whole idea: the person selling a desk is a ten-minute walk away, so you meet, trade, and go home. It's less a national marketplace and more a bulletin board for your block. If you've just moved and are still figuring out which neighborhood suits you, browsing its Karrot listings is a surprisingly honest window into what an area is actually like.

The app is Korean-first, but your phone's built-in translation handles it fine, and most listings are just photos, a price, and a short description. You'll pick it up in an afternoon.

The Manner Temperature (매너온도)

This is the part that confuses everyone, and it's genuinely clever. Every user has a manner temperature (매너온도) — a trust score shown as a number in degrees. Everyone starts at 36.5°C, the temperature of the human body. From there it moves based on how you behave:

  • Good reviews push it up. After a smooth trade, the other person can leave positive feedback, and your temperature slowly climbs.
  • Free giveaways push it up faster. If you list something as a free giveaway (무료나눔) — genuinely handing an item over for nothing — your temperature jumps more than a normal sale would. The app rewards generosity, and locals absolutely use it.
  • Bad behavior drops it. No-shows, rudeness, and canceled deals cool you down, and a low temperature is a visible red flag to everyone you message.

Before you agree to meet anyone, glance at their temperature. Anything comfortably above 36.5 with a few reviews is a normal, trustworthy trader. Someone sitting well below it, or brand new with no history, is a "meet in a public place and inspect carefully" situation.

The Three Ways to Trade

Almost every Karrot deal happens in one of three formats. Knowing which one the seller means saves a lot of confused messaging.

1. Meeting in person (만나서 거래)

The default, and the most common by far. You message the seller, agree on a time and place, and meet to hand over the item and the cash — or, more often, a quick instant bank transfer on the spot. You get to inspect the thing before you pay, which is exactly why it's the norm. The catch — and the etiquette — is who travels to whom, which I'll come back to.

2. Parcel delivery (택배 거래)

For anything too far to meet over, or small enough to post, the seller ships it. The rule foreigners always get wrong: the buyer pays the shipping cost, on top of the item price. It's standard, nobody negotiates it, and you settle the shipping when you pay. You usually send the money first and receive the parcel a few days later, so parcel deals lean harder on that manner temperature for trust.

3. Doorknob handoff (문고리 거래)

The contactless option, and a very Korean solution. The seller literally hangs the item — bagged — on their own front door handle (문고리), sends you the address, and you go pick it up, leaving payment by transfer. No face-to-face meeting at all. It's convenient and common for cheap or free items, but note the direction: you go to the seller's door, not the other way around. Which brings us to the one rule that governs everything.

The Unwritten Rule: The Buyer Travels

Here's the etiquette that quietly runs Karrot, and the one that'll mark you as clueless if you break it: the buyer goes to the seller. In Korea this is basically 국룰 — the "national rule," the thing everyone just knows without being told. The person who wants the item is the one who travels, meets near the seller's home, and makes it easy. Asking a seller to come to you, especially for a cheap item, reads as entitled and will get you politely ignored.

A few more small things that keep your temperature warm:

  • Show up on time. No-shows are the cardinal sin. If you're running late or need to cancel, message immediately.
  • Haggle gently, once. Light negotiation (네고) is fine — a polite "would you take a little less?" — but grinding a seller down, or lowballing hard, is rude. Many listings say 네고 불가 (no negotiation); respect it.
  • Don't ghost after reserving. If a seller marks an item 예약 (reserved) for you, you've made a commitment. Follow through or free it up.
  • Keep the meet normal. A quick greeting, a look at the item, hand over payment, a thank-you. The whole thing takes about ninety seconds.

A Real Trade, Start to Finish

To make it concrete, here's a normal one from my own phone. I was selling something, messaged back and forth with a buyer, and we settled on a Saturday around 8pm near Jamsil Han River Park (잠실한강공원). They picked a spot close to where they already were, I confirmed it on my map app, and we met at the agreed corner. They looked the item over for maybe thirty seconds, sent the money by transfer while standing there, said thanks — and that was it, both of us back to our evening on a warm night by the water. No haggling, no drama, both temperatures a little higher for it. If you've spent an evening down at the Han River, you've almost certainly walked past a dozen of these little handoffs without noticing.

Tips for Foreigners

  • Lean on your phone's translation. The listings and chat are in Korean, but auto-translate is good enough to trade confidently. A few set phrases — "Is this still available?", "Can we meet today?" — go a long way.
  • Meet in public for anything valuable. Convenience stores, subway exits, and apartment lobbies are the standard spots. Daytime and busy is safest.
  • Check the manner temperature first. It's your single best trust signal — use it before every deal.
  • Inspect before you pay in person. That's the entire advantage of meeting up. Test the zipper, power it on, check the screen.
  • Mind the etiquette and you'll be treated like a local. Show up on time, travel to the seller, keep it friendly — and it's worth reading up on the broader etiquette basics while you're at it.

Once it clicks, Karrot becomes the first place you look before buying anything new. A monitor, a fan, a bookshelf, a nearly-new coffee maker someone's giving away for free — it's all a few blocks from your door. Learn the temperature, pick your trade format, remember who travels to whom, and you'll be trading like you've lived here for years.