HANOI -- Every morning after waking up, Hanoi resident Lan checks the Zalo messaging app for what other residents in her roughly 300-unit condominium are selling that day.
Social media connects buyers to trusted merchants inside their own community

Instead of braving the outside world, more Vietnamese consumers are buying food and other necessities from neighbors via social media. (Photo by Tomoya Onishi)
HANOI -- Every morning after waking up, Hanoi resident Lan checks the Zalo messaging app for what other residents in her roughly 300-unit condominium are selling that day.