Seriously, Nexus are not even marketed or sold retail or with contracts in most countries, and the list of countries in where they can even be bought online is a very small list of countries. Samsung outsells Nexus 100 to 1 because they phones actually exist as a product someone looking for a phone can choose.
Motorola offers more storage than Samsung and almost all of their phones come with SD slots and is also outsold by Samsung 5 to 1.
That seems completely unreasonable, but in fact, one reason I like my Galaxy Note II is that it supports a 64Gb card.
(It sure ain't TouchWiz!)
It is mainly the large screen though for me, but the 64Gb card holds my music collection and some videos and a lot of reference books when I am in no position to stream anything.
I would love to see hard numbers on that, because it sounds like bullshit.
Most non-tech people I know have no idea what a Nexus phone is because there is no promotion for it. Those that have a Samsung phone got one because they knew it was popular, thought it took great pictures, and loved the screen.