Sure. Obviously this implies that the primary motive is return on investments rather than an ongoing income.
But what if (usual disclaimer apply) BFL again pushes the deadline and BTC reaches USD 1000ish in the next 3 months? Would the math still be the same? Going back the original question this would imply roughly USD25 per card per day income (minus costs), not bad aae?
That's a problem with BitCoin at the moment, who will spend while the price continues to rise so quickly? Of course, if big players like Amazon were to accept BitCoin this problem would be reduced.
If ASIC's dont ship and BTC reaches 1000 USD I shall be very happy but it might be a big blow to confidence in BitCoin if BFL turns out to be a scam or a flop.