Online marketplaces: buying, selling, and meeting strangers

Informational only. Names and features change; always check the app’s own terms and age rules in your country.

Online marketplaces are sites and apps where people list items or services for sale, often directly to other people (peer to peer). Some are built for local pickup; others ship nationwide or worldwide. Teens may use them to buy clothes, electronics, collectibles, or to sell their own stuff. The same features that make trading easy also enable scams, fake goods, pressure to move chat or payment off-platform, and in-person meetings with strangers.

Well-known general and hybrid marketplaces

• Amazon: huge catalog; many listings are from third-party Marketplace sellers, not Amazon itself. Reviews, return rules, and who you are dealing with can vary by seller.
• eBay: auctions and fixed-price listings; strong in used goods and collectibles. Buyers and sellers are rated; disputes go through eBay flows.
• Facebook Marketplace (Meta): local and shipped listings tied to Facebook profiles; chat often stays in Messenger. Very visible in many regions.
• Craigslist: simple classifieds, especially strong in the US; many categories are local cash or meetup deals with minimal built-in buyer protection.
• OfferUp: US-focused buying and selling app (historically related to the former Letgo audience).
• Nextdoor: neighborhood network; many areas have active for sale / free posts with local pickup.

Fashion, streetwear, and resale

• Depop: social, image-heavy resale (often Gen Z fashion); now part of the Etsy family of brands.
• Vinted: popular in Europe and other regions for second-hand clothes and accessories.
• Poshmark: US-heavy fashion resale with sharing and parties as part of the model.
• Mercari: broad second-hand marketplace (Japan origin; also used in the US and elsewhere).
• Grailed: menswear, sneakers, and designer resale with a community feel.
• StockX and GOAT: authenticated sneakers and streetwear; prices move like a market.

Handmade, vintage, and crafts

• Etsy: independent sellers for handmade, vintage, craft supplies, and digital goods. Not only individuals; many small businesses run Etsy shops.

Regional names you may hear (not exhaustive)

• Gumtree: classifieds in the UK, Australia, and other markets.
• Leboncoin (France), Kleinanzeigen (Germany), Marktplaats (Netherlands): large local classifieds in those countries.
• Carousell: popular for peer-to-peer selling in parts of Southeast Asia and beyond.
• Taobao, JD.com, and similar (China): massive commerce ecosystems; cross-border shopping has its own customs and scam patterns.

Why parents should care

• Age limits: apps often require users to be 18, or 13+ with rules teens may skip by entering a false birthday.
• Stranger contact: buyers and sellers message each other; pickup means meeting someone in person unless you strictly use shipping.
• Payments: wiring money, gift cards, or “pay outside the app” requests are common scam patterns.
• Counterfeits and empty boxes: especially for hype sneakers, electronics, and branded goods.

What helps at home

• Ask which apps they use to buy or sell, and whether meetups are involved.
• Agree rules: no solo first-time pickups with strangers, no home address in public listings, no payment off-platform for strangers.
• Use official in-app payment and tracking when shipping; keep chat on-platform until you trust the pattern of the deal.

Related: Creator content marketplaces (memberships & tips, not only goods) · Payment apps (G7) · Young people & money · Social media and DMs