China's Taobao.com, competitor to eBay, aims to open up site-wide transaction data so users can know about purchasing trends in world's market. Taobao next week declare plans to start big swath of its transaction and data, which combined from across site and prohibit any personally particular data, person said. User compare how well different brands are selling in item category like clothes or mobile phones, or call up demographic data to see how factors like gender and age range affect purchasing habits.

Taobao, also e-commerce outfit, permits users sell items at sale or from virtual store. Users shop for all and companies like Japanese clothes brand Uniqlo have official shops on site. Taobao hasn't decided if it will charge for access to its data, but users able to access raw data itself or contract with research companies to analyze it.

It had 170 million users and business value in 2009 is US$29 billion. Online retail Web sites allocate parts of transaction data with users. EBay has portal that displays famous searches in different categories, along with user subscription service for data like average selling costs and successful keywords for item listings. Taobao's strategy been moving from acquiring new users to offering services to current users, said Dave Carini, managing director of Maverick China Research, a technology consultancy.