If they are paying just the right amount, it makes no difference whether we sell or mine.
People are not going to pay the right amount though. So far it's clear they are are willing to far pay more for a Blade than it's likely to earn over the device life time - even if they get it within a few days of ordering.
So you think our customers are stupid then?

I take your

to mean that you are joking, but neither you nor organofcorti are the first to say those words, and I just want to get this off my chest:
Why do people have such a hard time coming to terms with the fact that value is subjective?
Just because they valued a 10GH/s blade at
BTC75 (or whatever) doesn't mean that if that device doesn't mine more than
BTC75 that they are stupid. Maybe they don't believe BFL will deliver, maybe they think Avalon will be late on all fronts, and maybe they are willing to gamble on that?
Even if difficulty did not ever increase from what it is today, it would still take ~ five months to return the initial cost. If the network increases only by the amount ASICMiner has promised, it will be enough to make it very unlikely that they'll get a return on their investment.
Or maybe they have bitcoins to burn, and want to help distribute hashing power around the network?
Or maybe they just value the bragging rights of having one of the first publicly sold blade mining asic units in the world?
Their reasons are their own, and for you to label them as stupid is insulting to everyone.
Maybe so.
My statement wasn't a value judgement on the choice to pay more per Ghps than a device is likely to earn, just that this seemed to be happening - and not just with Blade customers either. I'm certainly not saying that the decision to buy was stupid, just that the choice was apparently not motivated by profit. So in the short term, selling hashrate will be far more profitable than mining with it.