The first test by Wal-Mart Stores Inc. of discounting a product that captures the interest of a consumer collective resulted in the retailer offering a plasma TV at an 18% discount.

In a model that resembles the one offered by daily deal king Groupon—and in the latest sign that the limited-time deal craze has planted itself in the mainstream—the world’s largest retailer on Monday began offering a product and a proposed discount for that item on the Wal-Mart Facebook page. If enough consumers clicked the Like button below the product description, the retailer promised to honor that discount until supplies run out.

The first item offered under the CrowdSaver program this week is a 42-inch plasma TV from Element Electronics that Wal-Mart said it would sell for $398—which the retailer said was 18% off the regular price—if 5,000 consumers pressed the Like button.  Consumers who pressed the button first had to become a Facebook follower of Wal-Mart.

By Thursday morning, 6,000 consumers had indicated their Likes, a Wal-Mart spokeswoman said, an encouraging sign for the first product offering. The retailer has more than 1.9 million followers, according to its Facebook page today. “CrowdSaver is in a trial period,” the spokeswoman says. “We are seeing a good response to this.” The retailer, through a message on the CrowdSaver section of the Facebook page, told consumers to return later this week to purchase the discounted TV.

The spokeswoman would not say if the Element plasma TVs were overstock and if CrowdSaver gave Wal-Mart a way to dispose of excess inventory. Generally, the price of TVs are falling as the holiday shopping season approaches, according to a report from market research firm DisplaySearch, with prices for LCD TVs, the dominant technology, falling more quickly in the fourth quarter than for plasma sets.

The spokeswoman did say, however, that Wal-Mart will listen to customer segments—for instance, moms who comment on the retailer’s Facebook page—when deciding what items to offer at discounts through CrowdSaver. The spokeswoman adds that the number of required Likes before a discount kicks in could vary according to product.

Wal-Mart is No. 6 in the Internet Retailer Top 500 Guide.