"Nextdoor is now trying to localize social networks.(...)
Their original motivation for starting the site was to get individuals involved in civic issues, but they found that much of what people wanted to do was discuss crime, or get recommendations, or find local people to sell something. But their anecdotal experience is that these exchanges help forge the social networks that can be activated when civic issues arise. Moreover, they believe that these transactions help reinforce generalized trust of participants in their neighbors."
Via Artur Alves