Mediaplex, a digital technology messaging company, has announced that it now offers city-based geo-targeting, enabling advertisers to send individualized messages to website visitors based on the city
from which they access the Net. The technology is provided by Amsterdam-based RealMapping, a geo-targeting firm with a database of about four billion global IP addresses. The service will not work for
users whose ISPs route through one location, such as AOL subscribers, but company officials say it is effective for the majority of visitors.
