Yes and no. Because trademarks are market-specific, it is possible that someone else may have a trademark on "Groupon" in the context of say, dog food. So the

Yes and no. Because trademarks are market-specific, it is possible that someone else may have a trademark on "Groupon" in the context of say, dog food. So the trademark is not exclusive in that sense. However, each trademark holder would have the exclusive right to use the mark in their particular market.