Shares of Groupon Inc. fell 24 percent in after-hours trading Wednesday after the largest daily-deal website reported fourth-quarter revenue that fell short of analysts' estimates as consumer demand wanes for Internet coupons.

Sales were $638.3 million, the Chicago-based company said Wednesday in a statement. Analysts on average projected $640.2 million in revenue, according to data compiled by Bloomberg. The net loss widened to $81.1 million, or 12 cents a share, from $65.4 million, or 12 cents, a year earlier.

Groupon Goods, a service started in 2011 to help companies such as Dell and Garmin peddle thousands of marked-down items, has been bringing in a growing portion of revenue as demand cools for daily discounts. The e-commerce business is crimping profits as Groupon invests in infrastructure to store and ship physical goods, said Sameet Sinha, an analyst at B. Riley & Co.

"It's not a virtual business like the coupon business, where most of the costs are marketing," Sinha said in an interview before the earnings report. "You need to have a buying organization, logistics, delivery, returns, inventory management."

Revenue in the current quarter will be $560 million to $610 million, Groupon said in the statement. That compares with an average analyst estimate of $647.7 million.

The news was released after the markets closed. After ending the regular session at $5.98, Groupon shares sank $1.56 to $4.42 after the report.

The company makes money by offering discounts known as Groupons from businesses such as restaurants and nail salons. It then shares the revenue with the businesses.