who even goes outside anymore?
Sure, it's most fun to run when you aren't at home, but it's very possible to run it while you're doing other chores.
Or just run it on a lower setting while you're watching TV.
What's with telling YEARLY salaries?
It's not just a US thing. I've never actually thought of this until this post, but I'd think it's because taxes are done annually.
Your employer says they'll give you X amount a year, but you receive X-Y into your account. It's easier to talk about X, then to worry about how Y fluctuates.
It also makes it feel as if you're making more money. Raises for a year sounds better than when you divide by 12 and get the monthly.