NetRatings said Monday that it filed a patent infringement lawsuit against The NPD Group, alleging NPD is using methods for computer-use tracking that infringe on its patent. NetRatings, which provides Web metrics data under the name Nielsen/NetRatings, filed the complaint in the United States District Court of Delaware. NetRatings is seeking a permanent injunction and unspecified monetary damages from NPD for past infringements.
The suit recalls a long-simmering rivalry between NetRatings and Media Metrix. The NPD Group is a privately held market research firm that developed the technology for the original Media Metrix measurement business, which became Jupiter Media Metrix in March 2001, after it merged with Jupiter Communications. NetRatings nearly bought Jupiter in October 2001, but the deal was quashed because of regulatory concerns. Still, the deal dissolved Jupiter's patent suit against NetRatings. Media Metrix's measurement business is now a part of ComScore Media Metrix, which bought the business from Jupiter in 2002.