As a 'Metropolitan Statistical Area' (city & suburbs as analyzed by US census), Phoenix is 12th, with about 4.5M residents: https://en.wikipedia.org/wiki/Phoen

As a 'Metropolitan Statistical Area' (city & suburbs as analyzed by US census), Phoenix is 12th, with about 4.5M residents: https://en.wikipedia.org/wiki/Phoenix_metropolitan_area#Metropolitan_Statistical_Area https://en.wikipedia.org/wiki/Phoenix_metropolitan_area#Metr... The LA MSA is about 3x larger in population and packs them into 1/3rd the area – so way, way different in how attractive for rolling out a novel service. Population age and wealth probably also figure in.