Mate, you can't even be profitable with a decent gaming computer with a high end graphics card mining Bitcoin, how do you think USB mining will end up?
As many others before, do you realize that the said USB miner is using ASIC chips, the same as on an S9?
That tiny USB miner everyone laughs about is way better than the first ASIC Bitmain launched and can still compete in terms of raw hashrate with their second model , the S3, which does 440GH/s while the Compac F usb miner gets 300+.
I don't understand why people are fixated that much on the USB thing.
If you slap a modern ASIC chip on an usb miner it will have the same characteristics as an ASIC, the only limitation is that you can barely fit one while with a 3000w miner you get 3 boards full of chips.
What I am trying to say here is that instead of buying 6 Bitcoin USB-Stick Miners, you can buy one Bitmain Antminer S19 Pro and you will get a return equal to buying about 300 Bitcoin USB-Stick Miners.
If he's looking for profit, buy the s19, but be careful if you can run it at all in your house;
If he's looking to experiment with a miner for fun and not thinking of money buy a used old miner from two or three generations ago.
If he's just looking for a novelty item and a fun quiet thing with no money involved, yeah, the USB miner might be a thing.