Xaxis, the new venture of advertising giant WPP, has sparked privacy concerns after it was learnt that the company's database contains profiles of 500 million individuals worldwide.
The company says it has built the largest database of individuals' internet behaviour, which covers almost 100 per cent of the populations of the UK, US, Australia and eight other developed countries, The Indenpendant reported.
Xaxis, pools the data from many of the world's major websites, networks of online advertisers and other sources. This data is then used to provide targeted advertising to users based on their interests.
"The internet is an advertising-supported medium, and much of the web is free because advertisers want to put messages in front of people," said Brian Lesser, chief executive of Xaxis.
Xaxis is supporting the broader internet economy by improving the targeting of ads, while also playing by the strictest privacy rules, Lesser added.
The company says that all the data is anonymised and cannot be traced to named individuals.