This could rate in the stupidest workarounds, but it might help you.

Go to the Data Mapping Wizard,
choose Shaded Area,
Next,
select Add Demographics to the Map,
select US Demographic Data,
Next,
select Area in Square Miles, <none>, Zip Code,
Next,
Finish

You get a map shaded by Zip Code. I don't know if it will help, but it might be a start. All the best with this sad program helping your dream business.

Apollyon