Updated

Microsoft Corp. is bringing digital advertising to the grocery cart.

The software maker spent four years working with Plano, Texas-based MediaCart Holdings Inc. on a grocery cart-mounted console that helps shoppers find products in the store, then scan and pay for their items without waiting in the checkout line.

Microsoft's acquisition of aQuantive, an online advertising company, last year for $6 billion shored up the company's capacity to serve video ads onto these grocery cart screens.

• Click here to watch a video of the cart in action.

Starting in the second half of 2008, the companies plan to test MediaCart in Wakefern Food Corp.'s ShopRite supermarkets on the East Coast.

Customers with a ShopRite loyalty card will be able to log into a Web site at home and type in their grocery lists; when they get to the store and swipe their card on the MediaCart console, the list will appear.

As shoppers scan their items and place them in their cart, the console gives a running price tally and checks items off the shopping list.

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The system also uses radio-frequency identification to sense where the shopper's cart is in the store.

The RFID data can help ShopRite and food makers understand shopping patterns, and the technology can also be used to send certain advertisements to people at certain points — an ad for 50 cents off Oreos, for example, when a shopper enters the cookie aisle.

Microsoft said it is still working on how it will present commercials and coupons.

Microsoft is also working with MediaCart and ShopRite to help advertisers reach potential consumers based on past grocery purchases, which are logged when they swipe their loyalty cards.

"This is not all necessarily about bombarding consumers, about targeting advertising," said Scott Ferris, general manager of Microsoft's Advertiser and Publisher Solutions group. "It's about also making the shopping experience better for the consumer."

Advertisers will get more feedback about which commercials or coupon offers are effective, because customers either buy the products or accept the offers on the spot, or they don't.

But Ferris said neither Microsoft nor any advertisers will have access to the personal information consumers provide when they join the supermarket's loyalty card program.