I only have 3 GB of data in my data plan, which is always more than enough for me, unless I'm working over my cell connection. I could get more data, but doing that just to stream music (when I already have a working solution for such) seems silly. I think in the US people often have much more expensive and large data plans than elsewhere. (My entire cell phone bill is €12/month, including 3 GB data, and unlimited calls and texts.)

I also very regularly go places with mediocre cell service: country side, airplanes, boats, and festivals.