Groupon Takes Coupons Into The Social-Media Age

ADVERTISING AGE — While coupon mailers clutter the recycling bins of digital-oriented millennials, one startup has revived couponing for the Facebook and Twitter generation. Chicago-based Groupon has amassed 2 million subscribers to its website, and begun adding big brands such as Zipcar, the NBA and Blockbuster to its regular stable of local businesses. Only one year after launch, it has sold 1 million coupons and received $30 million in second-round financing from Accel Partners. According to a counter on its site, that's translated to more than $45 million in savings since November 2008...