Page is a not externally linkable
ccDan - 7:13 pm on Sep 1, 2006 (gmt 0)
Or 301 redirect to: [superdomain.dom...] Plus, in the case of zip codes covering multiple cities, you'd have a page asking, Were you looking for... (POPUP LIST).
Unless they host 50,000+ unique sites, with decent / unique content related to the specific zip codes they will be lost in the SEPRS.