While the Dropbox offer hasn't been universally accepted in the States, it has been agreed to by all the Canadian mobile operators offering the Samsung Galaxy S III. The free 50GB of storage for 2 years is not something to dismiss lightly considering it has a value of $99, which certainly makes it interesting that Verizon and AT&T didn't agree to it. Are the carriers planning on offering a Dropbox-like service themselves, or are they just paranoid about having it pre-installed on the phone? And whatever their objection to Dropbox is, some other carriers overseas seem to agree.
With more Canadian carriers offering the handset than in the U.S., the mobile landscape up north for the Samsung Galaxy S III is more competitive than in the States. This means that if any of the carriers up in Canada were to turn down the Dropbox offer, it could have meant the loss of quite a few pre-orders for the phone.With this in mind, it is a lot easier for those carriers up north to all fall into place together.