In a pronouncedly rare move, Facebook is the proud new owner of that photo-sharing app that all the kids are crazy about these days: Instagram. A company press release reported, "total consideration for San Francisco-based Instagram is approximately $1 billion in a combination of cash and shares of Facebook." Zuckerberg wrote a Facebook note about the acquisition -- also a rare event -- on Monday afternoon and explained that not much would be changing about the Instagram experience in the near term as Facebook is "committed to building and growing Instagram independently." This is notable because with past acquisitions like Hot Potato and drop.io, Facebook has more or less shut down the acquired services. But if we didn't express the rarity of the situation enough already, Zuck also promised not to make the purchase of such a popular service a regular occurence. "This is an important milestone for Facebook because it's the first time we've ever acquired a product and company with so many users," Zuck wrote. "We don't plan on doing many more of these, if any at all."

Correction (1:23 p.m.): An earlier version of this post said that Facebook acquired Aardvark. In fact, it was Google.