I can't see how this make sense. Even if you assume that it's useful for a device to have some bitcoins available, it seems much more efficient to either supply

I can't see how this make sense. Even if you assume that it's useful for a device to have some bitcoins available, it seems much more efficient to either supply them when the device is created or download them on demand. The cost of building a mining chip into the device plus the expensive power consumption plus the difficulty of maintaining a network connection to access the mining pool seems way more than the cost of just providing the device with bitcoins. A key point from the article is: "Crucial to this is the idea that bitcoin generated by embedded mining is more convenient — and hence more valuable — than bitcoin bought at market price and manually moved over to the site of utility." I just don't see that, especially if you assume bitcoins mined on the device are going to be much more expensive (because of less efficient mining and because of 21's overhead.)