EDIT: according to comments below, looks like its about 20+ petabytes which is actually a fairly large amount.
> As of October 2012, its collection topped 10 petabytes.
I'd be curious what it's grown to since, but google didn't immediately tell me.
1) They have it sitting unused presently. The nominal cost of providing it would be zero.
2) RRS is fine. So would Glacier be. This reduces costs further.
3) There is significant PR benefit to such a move.
Server amortization costs, future cost calculation planning, depreciation costs, power consumption, etc are all closely calculated and factored into budgets. Just thinking they can support that much data for free and at no cost, or minimal cost because it feels good is naive.
My point was you can't rely on them to keep said data available. Not that they couldn't participate.. but I wouldn't trust anything less than a "Lifetime" (of the company) or a 25 year minimum commitment as anything but transient.