It also said there hadn't been a change in its previously reported operating Q4 and fully year cash flows: $169.1 million and $290.5 million, respectively. And Groupon added that its non-GAAP, previously reported free cash flow, reflecting cash flow from operations less purchases of property and equipment, remained $155.1 million and $246.6 million, respectively.

Groupon pioneered the daily-deal market, where consumers buy discounts on restaurant meals and other services, and for which Groupon splits the revenue from the offers with merchants.

But the company said its financial-statement revision relates to the accounting for an increase in higher-priced deals -- those more likely to be refunded by customers. Last year, Bloomberg noted, the company began Groupon Reserve, a service for upscale deals such as a five-course meal at Santa Monica, Calif.-based restaurant Whist for $99.

The higher refunds widened Groupon's net loss by $22.6 million, or 4 cents a share.