Craigslist and eBay are great services when you're looking to sell unwanted items, but what about things strangers aren't likely to buy? On Bondsy, a new mobile app aimed at helping users barter and trade, several pounds of unwanted bacon were recently swapped for a bag of coffee beans, a collection of unused T-shirts traded hands for some plumbing services, and a smartphone found a new owner in exchange for a dinner. "There are a lot of things you own that aren't easy to put a price tag on," said founder Diego Zambrano. "But they often have a lot of value to someone in your social network."

Selling several pounds of unwanted bacon isn't easy

Bondsy doesn't have public listings organized into product categories. Instead, it focuses on private listings that are shared with friends, or friends of friends. "If you keep the audience intimate, it becomes a lot easier to trust the person you're trading with, and to list things that might be too strange to put up anywhere else," says Zambrano. I connected my Facebook and Twitter accounts to Bondsy, which found nine friends. When I shared an item with friends of friends, my circle of trust extended to over 600 people. Users on the service often offer one price for friends, and a slightly steeper one for friends of friends.

Jonathan Basker used Bondsy to offload a Nintendo Wii he no longer wanted. "I tried to sell it for months but no one wanted to buy it. I didn't just want to trash it. On Bondsy, I traded it for a nice houseplant," said Basker. "The cash value of the Wii wouldn't have made me happy, but the new plant does. The other guy also seemed to feel like he got a great deal. That's the nice thing about the barter system. Things have a value beyond this fixed value of cash."

"I traded [my Wii] for a nice houseplant."

Bondsy does allow items to be listed for a cash price, but the majority of things that appeared in my feed were being offered for free or trade. "There is a lot of stuff in your life that doesn't really make sense to sell, but also, you can't bear to just throw it away," says Zambrano. "Here you just snap a picture and offer it up." Users don't need to create an account, like they would on eBay — when you make an offer for an item, the app opens up a private chat between you and the owner. Unfortunately, this leaves all the hard work of arranging a time and place to make the swap up to you. And for now the network of users is rather small, limiting the number of available items and trading partners.

Bondsy, available only on iOS for now, fits into a hot class of startups in what's being called the "sharing economy," where users trade goods and services. Companies like TaskRabbit allow anyone to post chores or take odd jobs in order to make a few bucks in their free time. Services like Lyft and Airbnb help people to rent out their unused car or apartment to strangers. And Bondsy, which raised venture capital funding, is downright socialist in its approach the marketplace: "For now we aren't charging a fee or taking any cut of the transaction," says Zambrano. "The focus is on creating the best way for people to share and find stuff. If people love the app, the business will sort itself out."