Google to offer audience measures for advertisers

SAN FRANCISCO (Reuters) - Google Inc (GOOG.O) will offer advertisers a free media planning tool to help them locate target audiences on the Web, a company spokesman said on Monday, posing a challenge to existing Web measurement firms.

The leader in Web search and related advertising is making available Web measurement tools to advertisers and their agencies, based on the belief the more data ad customers have about their audiences, the more they are likely to spend.

The spokesman said audience measurement features are an outgrowth of Google's efforts to provide better media planning tools. He declined to provide further details on the plans, which will be announced in a company blog post on Tuesday.

The company was confirming details first reported by the Wall Street Journal about Google's plans to compete with established providers of Web audience measurement tools such as comScore Inc (SCOR.O) and Nielsen Media.

ComScore shares fell $1.69, or 6.1 percent, to $26 in extended trading following news of Google's planned media measurement service. Nielsen Media is a unit of Nielsen Co, which is owned by a collection of top private equity firms.

These Web measurement firms have roots in conventional media or retail audience tracking technologies. They have relied on selective surveys or customer panels to estimate Internet behavior. Their statistical approaches have faced criticism among advertisers and publishers over how comprehensive their data is. By contrast, Google's audience measurements would come from a fuller set of data collected directly from Web servers.

Web publishers would have access to the media planning tool, but are not the intended customer, the Google spokesman said.

(Reporting by Eric Auchard; Editing by Andre Grenon)