Facebook and Microsoft inch closer together with Skype

The most interesting part of Facebook’s new video-chat partnership with Skype is that it’s all happening on Facebook’s site.

Facebook users aren’t getting booted into a Skype app and aren’t being asked to sign up or log in with Skype accounts. Beyond the “Facebook + Skype” logo, it’s as if Skype wasn’t even there.

Why is Skype happy to take a back seat and just serve as an infrastructure play for Facebook?

In part, no doubt, because Facebook’s huge user base could drive growth for Skype. While Skype boasted “an average of 145 million connected users per month” in late 2010, Facebook now has 750 million users. There are also revenue-generating Facebook-Skype services on the way, Skype exec Neil Stevens said today, via Business Insider’s Matt Rosoff.

But Skype’s partnership with Facebook is also strategically sound — especially as Microsoft is in the process of acquiring Skype for $8.5 billion in cash. Microsoft and Facebook continue to inch closer, and it’s a great alliance for Skype to be a part of.

Google and Apple don’t need Skype, and now that Microsoft is about to own it, they probably wouldn’t even want to work closely with Skype. But a partnership between Microsoft, Skype, and Facebook looks impressive, at least in theory.

Could Facebook’s deal have even played a role in Microsoft’s decision to acquire Skype? Possibly.

“A few months ago, we started working with Skype to bring video calling to Facebook,” Facebook engineer Philip Su wrote in a blog post today. A few months ago, Microsoft hadn’t even announced its deal to acquire Skype yet.

It seems likely that Microsoft learned about the Facebook-Skype deal in the negotiation process. Facebook may have even given Microsoft the go-ahead to acquire Skype, probably after deciding that it didn’t want to acquire Skype itself. Either way, it’s likely that all three companies were okay with both deals, or today’s product probably wouldn’t have launched.

The bigger question is how long Facebook will think it needs Microsoft and Skype… and how long Facebook waits before it eventually goes out on its own for things like search and A/V conferencing.