Meanwhile, stiff competition from rivals such as LivingSocial, Amazon.com and Google, may be compressing margins, by offering participating merchants higher shares of deal revenue. Gross margin in the second quarter fell 2.4 percent from the first quarter, to 76.2 percent.

via Groupon shares fall 27% on disappointing results – chicagotribune.com.

Revenue from Groupon’s international business fell 4 percent in the second quarter from the first. The international business accounted for about 54 percent of total revenue in the second quarter.