Another giant step forward - if not for mankind, for Google stockholders - was announced Friday.

On that day, the Mountain View, California-headquartered internet search giant began offering US advertisers the facility to buy ads displayed on specific geographic locations via its much-used online local mapping and search service.

News of the launch is likely to trigger an outbreak of nervous tics at Yellow Pages and publishers of local phone and business directories - the traditional destination of advertisers seeking to link their services and brands to neighborhood outlets.

First launched last year in the UK, Google's Local Business service has been undergoing limited US trials since December, with the participation of selected advertisers such as Barnes & Noble.

The Google Local pilot enabled searchers using terms like 'bookstore New York' to auto-activate a map of Manhattan marked with small coffee-cup logos indicating the location of selected B&N stores.

As with other Google products, the advertising opportunities are auctioned to the highest bidder and billed on a pay-per-click-thru basis.

Data sourced from Wall Street Journal Online; additional content by WARC staff