2 Chicago-based sites are kings of coupons on Web

What does Chicago have that no other U.S. city has this holiday season? The top two busiest coupon Web sites.

Source: http://www.chicagotribune.com/news/ct-biz-groupon-coupon-cabin-dec28,0,1412197.storylink?track=rss

gifts online, personalised gifts, gifts for mothers, home accessories,