> I eat meat whenever my local supermarket has a piece of organic meat on sale because it would otherwise get thrown away.
I don't think that really works any more than the "look I'm killing the cows" argument. If they have to throw away packages each week, they'll buy less in the future, which in turn leads to lower production.
You assume the alternative is buying more. What if the alternative is buying twice a week but based on a different metric? Or buying less?
In general it's better to be accurate about cause and effect and then choose what to do. That way you can make sure the way you're measuring "good" is real.
