Not that those millions will exactly break the Facebook bank. The firm has just been valued at $50bn. This paltry sum is a drop in ocean and ensures Facebook's digital footprint reigns supreme.
The domain actually changed hands last November, but - to Facebook's chagrin - the Farm Bureau Federation revealed the figure at the annual "Voice of US Agriculture" meet-up yesterday. The FBF have something to shout about: this sale ranks in the top four all-time domain name sales, behind Sex.com (£8.3m), Fund.com (£6.3m) and Porno.com (£5.75m).
But what will Facebook do with this new domain? At the moment, it redirects to Facebook.com proper. But Smarta's money is on FB.com also becoming a value-added portal for users, comprising email and other online apps to compete with Gmail, Hotmail and Yahoo!.
Facebook's developers are in a bind. User are very reluctant to embrace change. Every new version and relaunch has been met with yowls of digital fury as Facebookers clamour for the old designs. FB.com presents a unique opportunity for the firm to introduce new bells and whistles, without tampering with the existing design further. At least, that's our theory.
They could be diversifying into potatoes or oil seed rape.
Tell us your theory below.