Ever since Facebook bought FriendFeed for $47.5 million, the tech press has been alive with speculation about what Mark Zuckerberg et al have up their sleeves. While much attention has focused on Facebook getting into the real-time search game, a Washington Post article Sunday comes the closest I’ve seen to offering the most plausable explanation.

Facebook wants to “own” social media, Chadwick Matlin writes. Matlin, in a well-reasoned piece, envisions how FriendFeed will combo with Facebook Connect in the company’s strategy. Some 15,000 sites already support Facebook Connect, which enables users to log into those sites with their Facebook IDs. If a Facebook user comments or adds content to that site, it’s fed back into their Facebook page. The sites love the attention, and Facebook gets more content (page views). Here’s where Matlin nails it:

”So here’s a theory: FriendFeed is going to become the companion to Facebook Connect; Facebook Connect pipes Facebook out to other sites, while FriendFeed’s technology pipes other sites in. . . .

“And unlike much of the tech press, I don’t believe this acquisition is about real-time search or a competition with Twitter.

“Instead, I think this is about social aggregation. Facebook bought FriendFeed so it could become the Huffington Post of your social life.”

Huffington Post, of course, aggregates news stories from all over the Web in addition to hosting its own contributors. It creates quick summaries to external content on bridge pages before the user can click to see the entire article. Huffington Post succeeds because it finds the content its users want and also monetizes it with its filtering system.

Because Facebook is a “walled garden,” meaning users’ pages are not open for the world to see (and Google to wade through), a user’s feed of friends’ news is limited to what those friends have posted to Facebook. Now add what FriendFeed aggregates from your friends’ other social accounts — Twitter, YouTube, Digg, blogs and many other places — and you’ve got an astounding amount of content that Facebook can serve up to readers. Not just social news, but friends’ recommended links posted elsewhere to content around the Web. Just as Huffington Post sells ads around its bridge pages to external content, Facebook will be able to do the same.

And Facebook has a goldmine of demographic data that advertisers will presumably use to target those new pages.

Wired magazine and others have written extensively about the ongoing war between Facebook and Google. Google obviously owns search in its current form, but it can’t crack Facebook’s walled garden. Now Facebook is pushing to own the social media space (as if it doesn’t already.) With that dominance, it can in turn also concentrate on social search, including real-time.

Which leads to the question. Long-term, are users going to search through the prism of what companies and content providers want us to see (Google)? Or are users going to want to search through the filter of what their friends are doing and what companies/content providers they recommend (Facebook).

As Matlin writes:

“. . . I’m sure Facebook will be happy to air your thoughts on the matter. Even if you write them on Blogspot, Google’s blogging network. After all, that’s why Facebook bought FriendFeed. [Blogspot feeds are included in FriendFeed]. So it could own you.”