By Ameet Sachdev | Success breeds imitation as Groupon, the Chicago-based company that offers coupons and discounts on its Web site, has learned.

The company on Friday sued Groupocity for violating its trademark.
Groupocity is a Tampa-based company that has the same business model as
Groupon, according to the suit filed in federal court in Chicago.

Groupon says that on Sept. 29, the U.S. Trademark Office registered its mark in connection with promoting the goods and services of others by providing a Web site by featuring coupons and discounts.

Groupon, which is active in more than 50 U.S. cities, including Tampa, sends daily e-mails to members offering discounts on local products and services. A certain number of people have to sign up for the deal in order to activate it. If not reached, no one gets the coupon.

Groupon said its competitor has caused confusion in the market place. The company said it has received calls and e-mails from Groupocity’s customers and retailers who had mistakenly believed that the Groupocity’s services emanated from Groupon.

Groupon said it asked Groupocity to stop using its similar name on Nov. 25 but to date its competitor has not made any changes.

Groupocity’s attorney responded in a letter contained in the suit that the company has been using the name since last July and that consumers are not likely to be confused by the names.

Groupocity officials could not be immediately reached for comment.