The future of Barnes & Noble's (NYSE:BKS) Nook Media subsidiary is up in the air. Not only did the bookseller discontinue tablet hardware, but also the company just announced that its CEO has resigned. The Nook segment's EBITDA losses nearly doubled last fiscal year to $475 million, and B&N appointed CFO Michael Huseby as the new CEO of the Nook Media subsidiary.

The news has sparked a fresh round of speculation that Microsoft (NASDAQ:MSFT) may step up as a possible buyer, and acquire the remaining stake in Nook. The software giant currently owns 16.8% of the business, publisher Pearson has 5%, and B&N owns the remaining 78.2%. This isn't the first time that investors have contemplated such a move, as separate reports in May said that Microsoft was considering a $1 billion bid.

Microsoft originally invested $300 million in Nook in April 2012, which valued the business at $1.7 billion at the time. The segment has lost over a quarter of that in EBITDA over the past year, and revenue has fallen 17% to $776 million. The leaked docs from May suggested that Microsoft was valuing Nook at $1.66 billion. That valuation seems optimistic in light of recent events.

At this point, it's rather unclear what Microsoft would gain from buying the rest of Nook. There are no hardware operations to speak of, and Microsoft is already building its own Surface family of tablets. The Nook brand name isn't particularly powerful, especially compared to its Windows platform. Nook has tried to expand its content into categories like movies and TV shows, but Microsoft already has those on its Xbox platform. As far as mobile apps go, Nook apps are based on Android and B&N just adopted Google Play, neither of which helps Windows Store at all.

The only thing that Nook has that Microsoft doesn't is e-books. But if Microsoft really wanted to compete with, Apple, and Google in the e-book market (which is extremely likely), it could just separately ink its own deals with book publishers to expand its ecosystem without having to spend hundreds of millions of dollars on acquiring Nook.

Acquiring Nook might be faster, but it's also much riskier and much more expensive. Save your money, Microsoft.

Fool contributor Evan Niu, CFA, owns shares of Apple. The Motley Fool recommends, Apple, and Google. The Motley Fool owns shares of, Apple, Google, and Microsoft. Try any of our Foolish newsletter services free for 30 days. We Fools may not all hold the same opinions, but we all believe that considering a diverse range of insights makes us better investors. The Motley Fool has a disclosure policy.