Location-based services isn’t for startups anymore.  AT&T, the biggest U.S. phone carrier announced its entry to the location-based ad camp on Feb 28th.

AT&T’s service is called ShopAlerts – http://shopalerts.att.com/sho/att/index.html?ref=portal.  It features ads and coupons from major retailers which are sent direction to subscriber’s mobile phones.  This service is only available in major cities in NYC, LA, Chicago, and SF and launch sponsors include HP, Kmart, JetBlue, SC Johnson, Kibbles ‘n bits, Nature’s Recipe and Got Milk’s campaign.

Even though it’s not an ideal lineup, it’s certainly a milestone for someone like AT&T to enter this space.  Last week I attended Navteq development conference in Shanghai Westin on the Bund and Saturday’s N-talk, what I noticed is there are China Mobile people everywhere, all interested in discussing topics ranging from Facebook SIM card to location based ads.  What does this mean for MadHouse?  For Domob? For Qieke?  For Jiepang?

Here are some background:

Technology: The technology behind geo-targeted ads is called “Geo-fencing“, an emerging technology which sets virtual perimeter aruond a particular geographic region.

Evolution:ShopAlerts, which launched last March from Placecastannounced a partnership with location provider Location Labs, in August. It uses Location Labs and services from other partners to locate the phones in the U.S. in order to send out alerts when creating campaigns for brands. When used by carriers like AT&T and O2, the carriers themselves provide the phones’ locations. Placecast manages the creation of geofences in both cases

Difference:Unlike foursquare, customers don’t need to launch any apps on smart phone or don’t even need a smart phone to get the geo-targeted coupon.  The potential user-base is by far wider in China compare with the U.S. if China mobile manages to execute.

Future:AT&T is already planning for more U.S. retailers and brands in the coming months but no word on adding more cities yet.

Sina blog @Kevin_Hobbes