Estimated profit of a $400 21's RaspberryPi-ASIC computer? So I'm thinking of buying one of the newly-announced $400 USD 21's RaspberryPi-ASIC computer.

How can I know the hashrate of its ASIC? How could I calculate the BTC profits I would get from it, per day?

PS: The purpose of buying it is not just for the mining profit, although I'm still interested to know on what scale of magnitude these profits are.
We know only some of the variables so it's hard to make a blanket statement. 

The chip mines at 50GH/s in the configuration given to consumers, while consuming 8W, for the whole device the consumption is likely in the order of 15W at the power point accounting for the consumption of the Raspberry Pi and conversion losses.

Power cost varies worldwide, but here's a general idea, all amounts are in USD. 

╔═══════════╦═════════╦════════════════╦═══════════════╗
║  Country  ║  $/kwh  ║ Cost per Month ║ Cost per Year ║
╠═══════════╬═════════╬════════════════╬═══════════════╣
║  Iceland  ║  5.5c   ║     $0.55      ║     $6.57     ║ 
╠═══════════╬═════════╬════════════════╬═══════════════╣
║ Indonesia ║   11c   ║     $1.22      ║    $14.40     ║ 
╠═══════════╬═════════╬════════════════╬═══════════════╣
║  Norway   ║   17c   ║     $1.89      ║    $22.33     ║ 
╠═══════════╬═════════╬════════════════╬═══════════════╣
║  Spain    ║   25c   ║     $2.79      ║    $32.86     ║ 
╠═══════════╬═════════╬════════════════╬═══════════════╣
║  Denmark  ║   33c   ║     $3.68      ║    $43.36     ║ 
╠═══════════╬═════════╬════════════════╬═══════════════╣
║  Vanuatu  ║   60c   ║     $6.67      ║    $78.84     ║ 
╚═══════════╩═════════╩════════════════╩═══════════════╝ 


The amount of gross income from such a device is essentially unknown, the Bitcoin network difficulty is constantly changing, and so is the value in USD of the Bitcoin being mined. 



Your income from a given hashrate is inversely proportional to the wider bitcoin networks hashrate, as it goes up your income goes down. The difficulty is adjusted every two weeks, and is growing single or double digit percentages per period at the moment. Planning ahead how much a miner will make even in one months time is essentially futile as a result of this unpredictability. 

Without counting the power costs, for the current difficulty of 72722780642, a 50GH ASIC will produce 0.01037 BTC per month.

If the difficulty and price has not changed, they could sell this for $3.28. If they live in Spain, Norway, Indonesia or Iceland, they made a tiny profit over their power bill which can go to paying for the $400 cost of the device, in Denmark or Vanuatu they made a loss.