So total per month for each one in $/kWh is
$350.00-USD 1x 280x 720kh/sec 0.09$/kWh 24/7 x 30 days = $16.20-USD
$1200.00-USD 12x usb miners 720kh/sec 0.09$/kWh 24/7 x 30 days = $1.50-USD
You would save $14.70 per month on your electricity bill, however you spent 650.00 more for the USB miners. It would take you 44+ months to make up for the cost.
So is it worth it? Not with AMD pumping out 20mn chips soon.
Also quick resell value of the 280x, around 300. USB chips that only do two things? Not worried about ASIC for scrypt at all.
Do you think all sticks assembled will collect dust while waiting for their lucky owner?
Do you think that thousands of chips produced will patiently wait to be transformed into USB sticks
I don't
If someone wants to pay for it, sure full steam ahead, esp the people who have high kWh numbers. I won't. You get no warranty from this manufacturer making the USB chips and try to resell it? You got a nitch market you gotta deal with. Video cards are easy to resell.