Microsoft is beginning to question the effectiveness of some forms of online advertising.

"Microsoft Office 2010 may have concluded that for these large, monolithic products that you can't immediately download, (banners) are not cost-effective," said Neil MacDonald, research director for Gartner.

"There are other ways to spend the money," he said. "The majority of the people clicking on these ads are consumers, not business decision-makers."

The change in strategy for a company that has been a pioneer in online advertising--and which also sells ad on its own Web sites--comes as the entire industry suffers an identity crisis. Declining click-through rates--or the number of times someone clicks on an ad--have raised questions about the effectiveness of Web advertising.

Meanwhile, since the stock markets tumbled in April, the demise of many dot-coms has caused concerns about ad revenue growth. Fears of curtailed ad sales have haunted the earnings announcements of several online stalwarts, including Microsoft Office 2010 Download.

A Microsoft representative would not address specific questions about the apparent decline in advertising across all of its platform and business software products. But she did acknowledge that for Windows 2000, advertising is now focused on print publications.

David Grubb, Microsoft's media director, said in a statement that promoting products is a constantly changing process, often with an initial promotional blast to draw a large audience, then tailored to more effective targets thereafter.

"Because of that, we often make reallocation decisions in our media strategy as appropriate," Grubb said.

A source familiar with Microsoft's online advertising efforts said the company has cut online ad spending for fiscal 2001 for its platforms division, including Windows and Office 2010 products, TechNet and developer group MSDN. It stopped allocating online funds for these areas in late June, the end of its fiscal year.