New York—U.S. marketers will more than double their annual spending on online-derived data sources over the next two years, investing as much as $840.0 million by 2012 on database lists and information about digital audiences and online behaviors, according to a new report by marketing consultancy Winterberry Group.

The report, “The Changing Mission of Marketing Data,” noted that U.S. marketers will gradually increase their spending on all marketing data, to $8.0 billion by 2012, but the entirely of that growth, as much as $1.5 billion, will be driven by digital vendors, such as online data compilers and exchange platforms.

Winterberry said the greatest challenge for marketers is managing “integrated data,” including contact information from online resources together with traditional database management vendors, publishers and e-commerce platforms.

The report was jointly sponsored by marketing data company Acxiom Corp. and data warehousing company Netezza Corp.