Why not all of the above? We can see some rounding already; http://investor.fb.com/releasedetail.cfm?ReleaseID=835447 says
Facebook today announced that it has reached a definitive agreement to acquire Oculus VR, Inc., the leader in immersive virtual reality technology, for a total of approximately $2 billion. This includes $400 million in cash and 23.1 million shares of Facebook common stock (valued at $1.6 billion based on the average closing price of the 20 trading days preceding March 21, 2014 of $69.35 per share). The agreement also provides for an additional $300 million earn-out in cash and stock based on the achievement of certain milestones.
There's rounding right there (23.1m * 69.35 is not a round number). And there's plenty of uncertainty about how much they will actually pay: how can anyone know how much of that earn-out will ultimately be paid?
There's rounding right there (23.1m * 69.35 is not a round number).
That sounds backwards to me. It looks to me like they started at the round 2.0, set 20% in cash, 80% in stock, found that required 23.1m shares of facebook and rounded that to three digits to get within 2% of the 1.6 they wanted.
Also, the incentive pay of 300m is 15% of the fixed payment, less uncertainty than rounding to 1 significant figure.
If it's worth saying, but not worth its own post (even in Discussion), then it goes here.
Duration set to six days to encourage Monday as first day.