I live in Texas, and I voted for Johnson. If I lived in Ohio I would have voted for Obama. It's hard to find numbers at the moment, but it looks like Johnsons's pulling 5%.
Is it because both are the contrarian play to something else?
GTFO Afghanistan ASAP (and their overall isolationist position) is one of the big ones. I could see someone who was pro-state intervention in domestic life, pro big taxes, etc. still voting Libertarian if he thought GTFO Afghanistan ASAP was the most important issue.
It's basically impossible to put US politics (or anywhere, really) on a strict left/right linear chart.
And the only state he came close to costing Romney was Florida. But even so, he would have lost it by over 3000 votes if all Johnson supporters voted for Romney.