A watermark embedded in a content (e.g., a printed document, digital audio, etc.)
includes data that associates the content with a remote store of related data.
For example, an image watermark may contain an index value that identifies a database
record specifying (a) the owner's name; (b) contact information; (c) license terms
and conditions, (d) copyright date, (e) whether adult content is depicted, etc.,
etc. Or a magazine advertisement may contain an index value that identifies a database
record specifying a related URL. Sometimes there are several back-and-forth exchanges
between the decoding device and the database. To speed response time, it is desirable
that this traffic be exchanged with a database that is located close—in network
proximity—to the device that decodes the watermark. In one embodiment this
is accomplished by first querying a master database with the zip code, or other
identifier, of the decoding device. The first database then responds by identifying
a second, nearby database with which further traffic should be exchanged.