Microsoft's latest productivity suite's first few weeks on the market have been disappointing, according to Stephen Baker, NPD Group's VP of industry analysis. The market research firm's Weekly Tracking Service found Office 2010 trailing its predecessor, both in terms of unit sales and revenue, when only the first two weeks were considered.

Baker blamed Office 2010's lackluster start to the fact that it was “launched into a saturated market” and that too in the middle of a “seasonally slow period for PC purchases which have, over time, proven to be a have a strong impact on Office sales.” However, Microsoft can take heart from that fact that Office 2010 has improved upon Office 2007's sales pattern so far this year.

“Office 2007 was a radical new design that certainly helped deliver a lot of curious buyers and it was launched nearly parallel with Vista, adding a good deal of promotional activity in the software aisle, both of which likely helped drive initial sales of Office 2007,” Baker wrote in a blog post. “While Office 2010 has many compelling new features, it is always an uphill battle to sell a high installed base product based on new features alone.”

The analyst sees tremendous promise in the key card program, which lets users activate Office 2010 on preloaded machines using a product key (no disc required). Baker revealed that the key card program currently accounts for “about one-third of the unit volume.”

Baker does not foresee web-based productivity applications posing any real threat to Office 2010 in the immediate future: “Over time it is certainly likely that we will see some slowdown in retail sales as consumers alter their productivity software habits, but that time is not now. Mainstream consumers have not embraced the concept of the cloud, nor are they likely in the short to mid-term, making most of the questions around free software moot.”