With Apple's market share steadily growing, thanks to ads which compare cool Mac kids to schlubby PC people, Microsoft is finally wising up: What it needs to advertise are PCs, not Windows. And cute girls!

Lauren, the star of Microsoft's latest ad campaign, wants a laptop with a 17-inch screen for under $1,000. She goes to the Apple Store; no luck. "I'm not cool enough to be a Mac person," she sighs as she drives away. She heads to Best Buy and finds one for $699. (Oh, by the way, though Microsoft is telling people that the people like Lauren featured in its new ads were hired on Craigslist for a "market-research study," Lauren is an actress.)

Kind of sad when the sole product quality you can tout is its cheapness, right? But that's always been the virtue of Windows: Not the quality of its software, but the business deals Microsoft struck with PC makers and retailers which make Windows machines the cheapest computers around. (Cheaper even than Linux machines, which have not achieved the volumes needed to beat Windows machines on price.)

It's a clever yet straightforward sell, especially for buyers in economic straits. There's just one problem with the strategy: What if Apple comes out with machines that match PCs on price? The Apple Store was Lauren's first stop. All it takes is one cheap laptop for it to be her only one.