I'm not seeing the same thing. The big chunk of red on the south side of the city is the ATL airport. ("Checking in! #delta #hartsfield) Georgia Tech, Downtown, Midtown, VaHi, Morningside, Druid Hills, Buckhead, Brookhaven, Marietta, Lake Claire, west side of Decatur and the south end of Sandy Springs are the areas I see in red here. These are all wealthy areas. All along the northern perimeter - which is mostly just white-collar businesses, is mostly red tinted and all along the rest of the perimeter is green. Other than Hartsfield Jackson, there is a pretty solid cone of red emanating from downtown into the north. I would say this is 100% spot on with mapping wealth to iPhones, although, I am not sold on the numbers that generated the map.