Love it or hate it, Facebook Marketplace is the largest online resale site today with more than one billion monthly users. A new study conducted by UBC researchers sheds light on the intricate web of trust, privacy and safety factors shaping users’ experiences on this popular platform.

Researchers interviewed 42 Facebook Marketplace buyers and sellers in the U.S. and Canada to uncover the factors associated with trading decisions.

“Concerns for physical and financial safety, as well as well-being, were top of mind among users, reflecting the inherent risks associated with trading with strangers—particularly because goods are exchanged in person,” said Dr. Konstantin Beznosov, senior researcher on the study and a professor of electrical and computer engineering at UBC. “Many participants hesitated to rate sellers, citing physical safety concerns and the challenge of balancing feedback with anonymity.”

Participants were also uncomfortable with the inseparable link between the Marketplace and Facebook, raising privacy red flags as personal details became intertwined with trading activities.

Because of these reservations, users remained vigilant while trading on the site, closely monitoring transactional signals, such as negotiation conversations, location preferences and signs of trader authenticity: perceived impoliteness, flirtatious or patronizing language, or multiple grammatical errors suggesting a foreign scammer.

“Despite these persistent trust concerns, most participants continued to use the Marketplace because it’s simple to set up and offers wide audience reach, and it’s effective in facilitating sales,” said Dr. Beznosov.

In response to the study’s findings, the researchers proposed increasing user safety and privacy on the Marketplace, including enhancing user understanding of the implications of sharing personal information, and adding features that strike a balance between privacy and trust—for example, by implementing a profile verification process.

Facebook, Dr. Beznosov added, should also offer more transparent communication channels for user feedback.

“At the end of the day, every market—even online platforms—carries an element of ‘buyer beware.’ But it’s always possible to create a safer, more trustworthy trading environment on Facebook Marketplace. We should be helping users to make more informed choices about the tradeoffs between benefits and risks in any online marketplace, particularly those in which goods are exchanged in person.”