Google linking online and offline worlds in new ad challenge

San Francisco

GOOGLE is testing a way to tie online ads to brick-and-mortar store purchases, a move that is whetting marketing appetites while fuelling privacy worries.

A product called "Google Attribution" was unveiled at a marketing conference this month in San Francisco by the Internet giant. Google has long been able to determine when users click on an ad and make a purchase, but linking online and offline habits takes its analytics a step further.