Why should you pay more to use your iPhone as a portable hotspot?

The latest iOS update enables you to turn your iPhone into a wi-fi hotspot, sharing your 3G connection with other devices – and even though iPhone data plans are capped, you still need to pay extra to use the feature. Why could that be? I think I know the answer.

There are only two possible explanations.

One, iPhone data is a different shape from Android data. It’s triangular, or maybe octagonal, and it gets stuck in the internet tubes.

Or two, the networks are bastards.