I was going to make some joke about freedom units etc. but instead I'll keep this as a serious suggestion.
I'm sure the vast majority of traffic does indeed come from the united states, but there must be a fair amount of visitors who aren't, right?
So I'm just proposing that wherever units or pounds are mentioned, perhaps in brackets or as a tooltip, show the metric equivalent.
It'd be very useful for the people who aren't familiar with the US/imperial system.
Not a major problem but I don't think it'd be difficult. I can't imagine many other statistics being used in a review knowing that 20%(?) of your readers can't understand it.
Anyway thanks for the site.