So if you get the AT&T or Verizon version of the Galaxy S III, you won't be getting a free extra 48 gigbytes of online storage on Dropbox. That sucks, considering that our European friends have it, and presumably Sprint and T-Mobile will as well. (And it's little toughter for AT&T fans to swallow since you can only get the AT&T GSIII in a 16-gigabyte flavor -- OK, throw a microSD card in there, but still.) But, hey, that's the carriers' right. They don't want to pick up the tab, Dropbox doesn't want to give it away for free (not that we necessarily blame them after what some folks did with the SGSIII promotion), and so we won't be getting the extra free space, a fact Dropbox has been happy to advertise in its help forums:
U.S. AT&T and Verizon customers
Select carriers have opted-out of the promotion on phones otherwise eligible. Unfortunately, AT&T and Verizon are among these carriers not currently participating.
It's not like you can't get a buttload of free Dropbox space already, though, with the usual 2GB of initial space, plus another 500MB for each referral, up to 18GB. (And if you have a friend with an HTC One phone, you probably can finagle a bit more, too.) If it's not worth it to AT&T and Verizon in this case, them's the breaks. End of the world? Not hardly. And if you really do need that 50 gigabytes, you can always pony up the $9.99 a month (or $99 a year) in that old-fashion, capitalistic manner.
Source: Dropbox; thanks to everyone who sent this in!