bullseyeThrough its 10-year deal with Yahoo, Microsoft has bought its way into being a major player in online advertising, serving an estimated 30 percent of the search-based ad market. But there’s one swath of advertisers who still shy away from spending their budgets on online ads: brand advertisers, who seek to raise the public awareness and image of a specific product, company or person rather than closing a sale immediately. Brand advertisers spend about two-thirds of the estimated $186 billion that makes up the U.S. advertising market, but only spend about 5 percent of this $100+ billion online.

A major roadblock to online brand advertising, according to Microsoft’s Advertiser and Publisher Solutions group, is that advertisers haven’t been able to get reliable data on the reach, frequency and audience composition of individual ad placements. Ad networks typically only provide reach and frequency numbers for entire sites, not for individual ad campaigns. So potential brand advertisers don’t know if they’re throwing money away, or planting their brand in front of a huge new audience.

Microsoft’s Reach and Frequency Planner — RF Planner for short — will use comScore data to predict how widely a specific ad buy will be seen, by whom it will be seen, and how often they will see it. “This will allow digital brand marketers to determine whether the impressions delivered by one group of ad placements are likely to be more valuable than those on another when the goal of the campaign is reach and frequency to a specified audience,” says a Microsoft press release on the comScore partnership issued this morning. “For example, the RF Planner will help advertisers forecast whether they would more cost-effectively reach women aged 18 to 35 with 10 million impressions on one group of placements versus 5 million on another.”

The system is already beginning a closed, invite-only beta phase. ComScore, who weren’t immediately available to comment, will provide Microsoft with detailed stats on individual branding ad campaigns, much more precise than generalized metrics for entire websites. Brand advertisers don’t want to know how many people read VentureBeat, they want to know how many people saw the ads for PG&E’s “We Can Do This” campaign, how often, and what their demographic makeup was.

The potential impact of RF Planner is huge. It could make brand advertisers finally feel as comfortable buying Web placement as they do TV spots. That will encourage them to spend more of the other 95% of their budgets online.