MasterCard Worldwide will shutter its MasterCard MarketPlace web site in June and reopen in July via an application on the Facebook Inc. social network. MasterCard MarketPlace launched about two years ago as an online mall that offered MasterCard cardholders discounts and offers from 25,000 participating merchants.

Cardholders who shopped on the MarketPlace earned points on their purchases, which they could then redeem on future MarketPlace purchases. Consumers have until the June deadline to redeem those points. The points will not transfer to the Facebook app, MasterCard says.

MasterCard did not respond to inquiries about why it is moving from its own web site, marketplace.mastercard.com, to Facebook. About 141.2 million people in the United States—nearly half the total population—have Facebook accounts, according to market research firm eMarketer.

Credit card competitor Visa Inc. launched Rightcliq, a social shopping and payment service that also offered discounts with participating merchants, in 2010. Visa closed Rightcliq last year.

At the Internet Retailer Conference & Exhibition 2012, Tom Funk, senior e-commerce manager, Green Mountain Coffee Roasters, and Jason John, senior director, marketing, Gilt Groupe, will speak in a session entitled “The many flavors of a social strategy: What will work for you?”