I chose "Other" as my usage is a combination of both, as ak.n770 suggested. The city I live in does not have a Wi-fi cloud, and while the university campus has it, I tend to cycle from location to location and so I cannot use the tablet on the move.

So: indoors: always-on, outdoors, on-demand. I refuse to subscribe to a cellular data plan until we get a decent plan here comparable to those in European countries: $10-$15 per month, 3G speeds, no limitation on tethering to other devices.