niDe mentions something everyone already knows, but it's an importnat reminder all the same:

As long as you've got the attrition research at the smelter that stops you from getting attrition when stationary, your merchant will be fine once he gets there.

See, I consciously knew that the smelter line reduced attrition and prevented attrition when stationary. But I never really considered applying that benefit to merchants in enemy territory (or on the edge of your territory). D'oh! It's good to keep hearing this stuff; you can learn new stuff everyday. (Unless you're Myst.)
posted by Tim at 6:49 PM