“In the past few months the number of changes that the U.S. Postal Service (USPS) has pushed through in terms of the coverage area for ZIP codes is more than we’ve ever seen,” stated Darrin Clement, CEO of Maponics. “For example, in the San Francisco Bay Area, in just three months, 26% of the ZIP Codes changed.”
According to Clement, most of the change is from consolidations, as they’re closing post offices rather than adding new ones, driven by lower and lower mail volumes.
http://www10.giscafe.com/nbc/articles/view_article.php?section=CorpNews&articleid=762251