If you are not familiar with Ad Planner, Google described it as:

…a research and media planning tool that connects advertisers and publishers. When using Google Ad Planner, simply enter demographics and sites associated with your target audience, and the tool will return information about sites (both on and off the Google content network) that your audience is likely to visit. You can drill down further to get more detail like demographics and related searches for a particular site, or you can get aggregate statistics for the sites you’ve added to your media plan.

Apart from making it available to everyone, Google has added some features to Ad Planner. Features include the abilities to:

- Define your audience by keywords and geography
– Manage your site results
– Analyze you media plan
– Get International demographic data

They have enhanced the geo-targeting capabilities, which should make for more relevant ad-serving. They’ve added three new site ranking methods so you can decide how you want your site results ranked and displayed. "You can choose between sites most likely to attract your target audience, larger known sites to increase your campaign scale, or a balance between the two," says Google. "By applying other site filters, you can narrow your search to only sites that accept ads, sites in specific categories like ‘Video Games,’ or sites that end with a particular domain suffix like ‘.edu.’"

They’ve also added a new bubble chart, which helps you compare sites in your media plan based on demographics, frequency, traffic, and unique visitors. As far as demographic audience data, they’ve added a few countries like France, Germany, Italy, Spain, and the UK, and they plan to ad more in the future.

The new ad planner features should come in handy not only as the holidays roll around, but as businesses reallocate their marketing budgets and test different advertising strategies. They’re going to need all of the data they can get.

A lot of us following the search industry thought Google’s move into providing, for free, the kind of data about website traffic and where it goes would be a tremendous boon for its advertising clients. Through the Google Ad Planner, one should be able to determine with a reasonable expectation of accuracy where the best places for their advertising exist.

Battelle dug into this with a look at comScore and the data it provides about traffic hitting third-party websites. On Battelle’s blog, he showed how the numbers coming from comScore’s panel-based approach hewed much closer to real traffic levels on a monthly basis than Google.

“The world expected that Google, with its unparalleled access to web-wide data, would validate publishers’ concerns and show that Comscore’s numbers were significantly under-reporting reality,” said Battelle.

“Turns out, the reverse is true.”

ComScore chairman Gian Fulgoni served up a couple of samples of data as evidence. One compared monthly traffic figures for 20,163 sites from comScore and Google Ad Planner; the second smaller sample looked at sites that are part of Google’s AdSense network.

Both comparisons showed far less traffic by Google’s reckoning, though the AdSense network member sites seemed to be less undercounted by Google. It doesn’t sit well with Battelle, who noted comScore’s observation of a “significant bias in Google Ad Planner data” pushing ad planners toward Google’s partner sites.

This may be happening as a result of Google biasing numbers toward what it gleans from usage of its Toolbar by online surfers. Others have made that claim, but the real issue of underreporting traffic is the disappointing problem. How can Google, with its access to data, provide figures so easily disproved publicly?

Why try and track down the handful of sites that will provide the best potential for conversions yourself, when Google wants to do it for you? Some webmasters with AdWords campaigns will have the chance to take advantage of this, Google announced today.

“When using Google Ad Planner, simply enter demographics and sites associated with your target audience, and the tool will return information about sites (both on and off the Google content network) that your audience is likely to visit,” the company said on its Inside AdWords blog.

“You can drill down further to get more detail like demographics and related searches for a particular site, or you can get aggregate statistics for the sites you’ve added to your media plan.”

We speculated yesterday that the rumors of this tool could be why companies like Google’s partners at Publicis Group weren’t all that concerned about Google and Yahoo teaming up on the contextual search ad market. Being able to pull up a group of sites that fit into one’s plans with a few clicks should be a powerful attraction for ad clients.

Google will roll this out slowly, with the first openings available by invitation only. The company has long since learned its lesson about opening services, as the painful issues surrounding its free Analytics launch demonstrated a need to manage the influx of demand.