Comparison shopping network and consumer ratings service provider Shopzilla Inc.is mashing together its specialties with the launch of RobotOatmeal.com, a coupon site that displays only  valid promotional codes for offers available from retailers that participate in its Bizrate Insights Seller Ratings Program. The company says 5,200 e-retailers participate in that program.

Offer listings on Robot Oatmeal display when a code was last used by a shopper so others can see before clicking that it is still valid. The click—for now at least—is free. Shopzilla says they are not charging affiliate commissions or click fees for traffic directed to a retailer’s web site at least through the end of the year. “Down the road the goal is to develop models that are optimal for retailers, and do not impose perpetual monetization,” a Shopzilla spokeswoman says.

Jewelry e-retailer Blue Nile Inc., No. 71 in the 2013 edition of Internet Retailer’s 2013 Top 500 Guide, has coupon codes on the coupon site, which officially launched last week but has been in test mode for several months. Shopzilla will promote RobotOatmeal.com at its booth during the Internet Retailer Conference & Exhibition next week in Chicago.

Consumers who search for Blue Nile’s offers on the site get a list of live offers, along with the number of times the offers have been used, when they were last used was and when they are scheduled to expire. For example, a Blue Nile 10% off coupon code displayed this week shows it has been used 43 times. The coupon expires May 30 and was last used successfully by a customer 10 hours ago. “Robot Oatmeal was able to drive excellent traffic and tens of thousands in gross merchandise sales in a short period of time,” says Jon Sainsbury, vice president and head of strategy, Blue Nile.

Shopzilla says displaying only live offers and the times they were last used addresses problems that come up when a consumer, at checkout, tries to redeem a code at checkout that comes up as invalid. It says that frustrates consumers and leads to greater customer service inquiries.