Feefighters has been bought by Groupon Inc.

Feefighters, which earns money by referring small companies to a handful of credit-card processors under the “comparison shop” signature, has been bought by Groupon Inc.

The company, which was started by students from the University of Chicago’s Booth School of Business, raised $1.6 million in January from Hyde Park Angels, i2A Fund, OCA Ventures and Sandbox Industries. Most employees will join Groupon, CEO Sean Harper said on his blog post Friday. Terms of the deal weren’t disclosed.