I did get multiple invites to sign up for NextDoor. Some neighbor apparently told NextDoor to invite me to sign up, when first getting into the neighborhood.
I didn’t like the idea of such a “clan” approach. It felt like I would be joining a “family” like that of “Rosemary’s Baby.”
Yes, they plat the neighborhood lots and then try to find an email associated with it. That becomes the “invitation” tool.
I find it extremely invasive.