Internet fraud prevention software developer 41st Parameter Inc. revealed Tuesday that online market research firm MarketTools has selected 41st's flagship PCPrint Device Identification product for its data validation needs. 41st explained that MarketTools will use PCPrint and its newly released companion application TrueSample to ensure respondent qualification and to eliminate duplicate responders. The financial impact of the customer win was not disclosed. MarketTools is a privately held company headquartered in San Francisco. 41st Parameter is based in Scottsdale, Arizona and is venture backed by JAFCO Ventures, Kleiner Perkins Caulfield & Byers and Northwest Venture Partners.