I agree with GrannyGeek. I think the significant numbers of Linux netbooks out there has a lot to do with Linux support starting to show up on hardware commonly used with netbooks, notebooks, and laptops.
Of course USB keys that don't say Linux work equally well. Maxell didn't do anything to make it work with Linux, of course. They just acknowledged that Linux exists
eMachines EL-1300G desktop, 1.6GHz AMD Athlon 2650e CPU, 4GB RAM, nVidia GeForce 6150 SE video
CentOS 6.5 (will try VL64-7.1 soon)
Toshiba Satellite A135-S4727, Intel Pentium T2080 / 1.73 GHz, 2GB RAM, Intel GMA 950
HP Mini 110 netbook, 1.6GHz Intel Atom CPU, 2GB RAM, Intel 950 video, VL 7.1