As a guy that's been mining for a few years now, I can get behind the idea of mining space heaters. I even wanted to place a small mining farm in the furnace room and then control the vents with individual thermostats to distribute the heat, dumping excess heat as needed.
But mining on a phone, it's just not reasonable. You could put the same chip on a USB stick and it would perform better.
Serious mining makes for some serious heat. If I'm 21 the household heating market is where I would target.
Water heating, Electric blankets, some cooking, pool heating, greenhouses maybe,
sure, they will go after those mkts too. but, imo, smartphones is the Big Kahuna. that is where the greatest money to be had lies.
remember, those OEM's that understand Bitcoin want to grab the majority of mkt share in developing nations by offering severe discounts to new previously unbanked customers. get the phone into their hands, lock them in, and worry about significant monetization later. the only way to do this, in the 21 model of mining chips, is to make the smartphones hash as a payback. whether mining "on it's own" will be profitable or not, it's hard to tell. but it could be with enough efficiency in the chip, assuming customers will attempt to pass on charging costs to "others", and coordinating the hashing power to generate blocks. either way, i don't think that's the main thrust. they want to get Satoshi's onto ppl's phones so as to allow the phones to "negotiate" micropayments for all sorts of unimaginable things like parking, fast lanes on hwys, who knows. the OEM's will have one huge coordinated network to which they can sell all sorts of other products and services as well. it's also their stated objective to decentralize mining which i think is a worthy goal even if it means they lose money on it. i've seeing all sorts of crying about "centralization" as a result. that's ridiculous. who honestly thinks that bringing on millions, if not billions, of new individual miners into the economy will do that? do you honestly think the #pools we have now will stay constant and just absorb all this new value? no way. as many new pools will crop up as device manufacturers who are willing to do this. in fact, each OEM should set up their own pool if they want to maximize the gain. it's easy. i ran my own sort of pool back when i was pointing 15 or so of my own miners at my stratum solo mining server. and i'm not a geek or CS. it was relatively easy. all sorts of new pool operators are going to come out of the woodwork to take any outsourcing that might occur. why not? free money in fees for easy work. no, we are going to see a mushrooming of the absolute #pools as well as a spreading out of the distribution into a much more decentralized piechart than we've already seen.
there will be also many ppl here in developed nations who will want these mining phones. esp with all the free electricity we have access to.
if you haven't listened to the audio dropt posted above, you should. it highlights and expands on many of the things i have been saying about this.