[ZenPro]

I am curious how this can be possible?

Does FB and Foursquare utilise broadly similar geo-location technology from within the mobile device?

Not saying you are incorrect - just wondering if a technical expert could elaborate on the accuracy.

[maxerickson]

They buy different starting data sets.

I guess most services also use things like the free GNIS data set from the U.S. government (it has good coverage, but the geocoding is not amazing).

Edit: And an entity like GNIS actually has less resources than Foursquare gets with its army of users (or at least, a lot less feedback generation).

[pbreit]

Probably more of a human thing than technical. The accuracy benefits from crowd-sourcing and Foursquare is used relatively significantly more in the US.