GA - missing US postal code areas (not all have areas)

[rothtd]

I was troubleshooting a complaint of missing postal code area geometries from GeoAnalytics. I didn't previously realize this, but not all postal codes (in the USA) have areas. Some examples: 77001, 77052, 77202, 77203:

These postal codes are in the GeoAnalytics location database for point geometry (they have center point coordinates)

But they are not in the GeoAnalytics location database for area geometry.

As you can see, 77001 has no area:

http://maps.huge.info/zip.htm

I didn't realize this, so I hope this helps someone.