Microsoft purchased an 18 percent share in Barnes & Noble’s Nook business for over $600 million this week.

Of course, that’s after buying Yahoo’s search business in 2009. And billions more to partner with Nokia to put Windows software onto its phones. And another $8.5 billion to acquire Skype.

Microsoft is trying to use money in lieu of innovation. Investment instead of ideas. The company simply isn’t investing in innovation as much as its acquisitions.

It’s why Microsoft’s share price is about half of what it was in 2000. And it’s why Amazon’s and Apple’s stock prices are soaring. Because the latter two companies are paving new roads, innovating their offerings and their marketing aggressively.

Meanwhile, Microsoft is using acquisition as an ineffective shortcut to innovation.