A sign marks the location of the Groupon headquarters in Chicago, Illinois. US Internet coupon deals website Groupon launched its China venture on Monday in partnership with local web giant Tencent, looking to tap into the world's largest Internet population.(AFP/Getty Images/File/Scott Olson)AFP – US Internet coupon deals website Groupon launched its China venture on Monday in partnership with local web giant Tencent, looking to tap into the world’s largest Internet population.