To me, hacking a device is quite different than hacking a promotion. When you hack a device, there's usually no victim. However, when you hack a commercial transaction, there typically is a victim because most transactions are zero-sum (or at least the transaction surplus is zero-sum).
It made me laugh too, and I got the sarc, but I think it's the last bit which really killed the karma... And we're lauding this accomplishment? Or maybe add a </sarc> next time just to make it clear for everyone :)
If it was indeed sarcasm then it was too subtle for HN. I mean if you had posted that on 4chan then it would be blatant sarcasm, but people on HN take themselves a little to seriously so it's a lot harder to tell.
At least this first part seems close to most definitions of hacking I know.