Sources covering the entire United States
Zip Code Business Patterns by NAICS (Census Bureau). Total number of establishments and number of establishments by employment-size classes by detailed industry. Data on mid-March employment, first quarter payroll, and annual payroll are summarized by ZIP Code without industry detail. Data are collected annually. See also the earlier Zip Code Business Patterns by SIC.
ZIP Code Statistics from the Economic Census (Census Bureau). Establishments, sales, payroll, paid employees by NAICS industry.
Census of Agriculture
National Agricultural Statistics Service Quick Stats includes 2007 Census of Agriculture data by Zip Code.
ZIP Code Statistics (Census Bureau). Census Bureau products that offer Zip Code level information, many of which are CD-ROMs for sale.
FDIC Institutions Directory (Federal Deposit Insurance Corporation). Look up the locations of all offices (branches) of banks or thrifts insured by the FDIC.
Home Sales Information (Yahoo). Database of home sales prices. Searchable by specific address or Zip Code.
Media Trackers (The Center for Public Integrity) enables you to find out who owns the media in your area.
Sources covering California only
Rand California (Oviatt Library subscription). Includes the following:
Housing Foreclosure Statistics. Contains the number of housing foreclosures since 2002 for most California counties, cities, and zip codes.
Housing Prices and Transaction Statistics. Reports the number of transactions, sales prices and dimensions of residential housing for most California counties, cities and zip codes by housing category since 2002.
Sources covering Los Angeles area only
Residential Vacancy Data (City of Los Angeles Department of Water and Power: distributed by the Los Angeles Housing Department).
Economic Alliance of the San Fernando Valley Virtual Library. While statistical compilations at this site generally are by community name within the San Fernando Valley, some of the data is mapped by individual Zip Code. Site includes the San Fernando Valley Almanac and Factbook.