Fair point about setup costs, but the marginal cost (which is what really counts over the long term) is negligeable in both cases.

Things are improving as I say in the piece, but it's worth noting that here in the Czech Republic I still have to pay nearly $200 for a month of data roaming in the US with a 200Mb cap. And that's if I go to the trouble of signing up for a special roaming plan, otherwise I could easily spent 10x that.