The problem for the Web's major ad services is extracting value from the tons of "remnant inventory" and out-of-the way pages that constitute the bulk of the Web. This morning, DoubleClick said it may have its own unique solution.

DoubleClick this week rolled out a new team and a new technology aimed at improving its ability -- and probably, that of prospective parent Google as well -- to pool together ad inventory for Web publishers, some of which are now banding together to form their own ad networks.

According to written statements released by DoubleClick this week, the company's new "publisher solution" will "address media fragmentation" by making it easier for Web publishers to aggregate and sell inventory in vertical networks. It revolves around enhancements to DoubleClick Revenue Center, including upgrades to its DART for Publishers (DFP) ad forecasting and reporting tools and DART Sales Manager ad sales software.

This new strategy follows a very different approach to handling online ad inventory than Yahoo, that major competitor of Google's that Microsoft has been attempting to acquire. Essentially, Yahoo's strategy -- picked up through the acquisition of Right Media -- is to build large "advertising exchanges" where ad inventory is traded in a way that's roughly analogous to trading shares on a stock exchange.

By contrast, DoubleClick's strategy is to collect Web sites with similar content and tastes together, pooling their ad inventory together into bigger blocks. To continue the stock exchange analogy, this new strategy is more along the lines of "holding companies" that represent pools of similar industries' stock.

While in the throes of fending off Microsoft's acquisition efforts, Yahoo has encountered competition for its strategy from the QuadrantOne ad network now being formed by Hearst, the New York Times Company, and other Web publishers.

Yahoo's own existing ad network also encompasses Hearst, in addition to Cox, Media News, and about 15 other newspaper chains.

The compexities of these interrelationships could raise some intriguing possibilities since, as some see it, Yahoo's strategy can actually operate on a complementary path to that of DoubleClick.

Meanwhile, Google's pending acquisition of DoubleClick still awaits approval by the European Commission (EC). While it's waiting, Google has been making some positive changes in its own advertising strategy, say some observers.

In a blog posting last week, ComScore's Magid Abraham and James Lamberti took issue with interpretations by financial analysts that a recent decline in paid clicks on Google is an indication of either a potentially weak first quarter outlook for Google or a sag in the overall online ad market.

Instead, the drop in Google's paid click metrics from December 2007 to January 2008 is "primarily a result of Google's own initiatives that [brought] a reduction in the incidence of paid listings and, therefore, the opportunity for paid clicks to occur," according to analysts for the Web analysis firm. "In addition, the reduction in the incidence of paid listings existed progressively throughout 2007 and was successfully offset by improved revenue per click."