Netbooks \u2014 or in Microsoft parlance, "small notebook PCs" \u2014 now account for between 10 and 20 percent of worldwide PC sales, depending on where in the world you live.Microsoft's Windows XP OS is running on a very comfortable 98 percent of all netbooks sold at retail in the United States, according to market research firm The NPD Group.One way the company is putting its netbook market clout to use is with a new post on its Windows Experience blog listing six tips to consider before slapping down the old credit card for netbook.Despite the growing popularity of these small wonders, Microsoft is still seeing netbooks being used mainly as portable "companion PCs" to traditional desktops or laptops. Ben Rudolph, senior PR director for the Microsoft's Windows Client group, says that most people use a netbook as a multimedia mobile device while traveling or commuting more than as their main computing machine."I don't see them replacing the traditional laptop or desktop, but adding more to what you can do on the go \u2014 and the multimedia features will be more accessible when Windows 7 comes to market," he says.Rudolph adds that while enterprises will obviously require more network management and security of netbooks than a consumer would, business users should ask themselves many of the same questions as consumers before buying netbooks. The main one: Will it work with my stuff?Here are the six key netbook purchasing questions that Microsoft highlights in its blog post (Click here to read the full post): Is it easy to use? Will it work with my stuff? Is it the right size for me? Does it have the hardware horsepower I need? Will I be safe online? What level of support do I need? Are you a Tweeter? Follow me on Twitter at twitter.com\/smoneill. Follow everything from CIO.com on Twitter at twitter.com\/CIOonline.