mining litecoins in the cloud

I wondered the other day if it was cost-effective to mine litecoins on AWS or Compute Engine. The instance prices are low enough that I could run a high-CPU or a GPU instance for half a day or so, and not worry about what it would cost me. But could I mine anything substantial in that period? Litecoin uses scrypt instead of SHA-256, and is biased towards CPU/GPU mining (as opposed to using an FPGA or ASIC miner).

I used a cpuminer; for comparison purposes, a 2.66 GHz Core 2 Duo Macbook Pro (mid-2009) can do about

thread 0: 4104 hashes, 4.76 khash/s
thread 1: 4104 hashes, 4.71 khash/s
Total: 9.47 khash/s

An n1-highcpu-2 instance on Google's Compute Engine platform costs $0.131/hour, and has two virtual cores. It can do

[2013-12-03 17:33:06] thread 1: 4104 hashes, 4.45 khash/s
[2013-12-03 17:33:06] thread 0: 4104 hashes, 4.45 khash/s

Not a whole lot better than the laptop. All right, let's try n1-highcpu-4 ($0.261/hour):

[2013-12-03 17:40:06] thread 0: 21996 hashes, 6.36 khash/s
[2013-12-03 17:40:06] thread 3: 24636 hashes, 6.45 khash/s
[2013-12-03 17:40:07] thread 1: 27936 hashes, 5.67 khash/s
[2013-12-03 17:40:08] thread 2: 41640 hashes, 6.58 khash/s

According to a litecoin calculator I used, at 25.06 khash/sec I can mine about 0.01 ltc every 24 hours. I'd end up spending just under $6.27 to mine $0.33 worth of litecoins.