I don't see this working in my neighborhood, like at all, mostly because my neighbors are predominately senior citizens or just about there. Of the 20% or so within my demographic, we've got our own social networks in the greater metro area. Honestly, I think my general perspective is that people in my region buy a house for privacy moreso than to be all personable and economically associated with neighbors - there's always 'burbs with HOAs for those types of folks.
I could see it working in the more dense, downtown apartment / condo markets, but the socio-economic status of those folks is pretty affluent. They don't need to ask neighbors for pet sitting or repair because they've got buying power. And their own social networks for referrals...