Vendors / Bing.com

Bing.com, a unit of Microsoft Corp., has a comparison shopping engine that helps consumers find deals on the web and receive cash back on their purchases. Web retailers can sell their products on Bing on a cost-per-acquisition basis. Because Bing Shopping uses a CPA model and pay-per-click bidding process, retailers don’t have to invest in fees traditionally associated with PPC campaigns. To advertise with Bing Shopping, web retailers must meet certain requirements, including being U.S.-headquartered.