Microsoft's hopes of Office 2010 breaking adoption records may have been a little overambitious, with NPD reporting that sales are "a bit disappointing" thus far. The updated productivity suite hit stores two weeks ago, and both units sold and dollars earned are lower than Office 2007's debut performance. That said, shipments are "in line, and in fact slightly ahead of" sales trends for Office 2007 this year.

The research group cites various reasons why Office 2010 hasn't stormed out of the gates, but the largest is simply that users don't have as much of a reason to upgrade as they did with previous iterations. By comparison, Office 2007 offered "a radical new design" that enticed curious buyers, and it launched alongside Vista, adding a "good deal of promotional activity in the software aisle." Office 2007 also arrived around the holidays instead of the summer, which is traditionally slower for PC purchases.

Before you say it, NPD dismissed the impact of free productivity products, saying that enough consumers don't currently know about options like Google Docs, Zoho and OpenOffice. Despite the slow start, Microsoft may have secured an additional revenue stream from its key card program, which makes it easier for new PC owners with pre-installed copies of Office 2010 Starter to obtain a full edition. So far, a third of Office 2010's sales have come from the new licensing system, and that number could increase.