How do you judge the PR damage of a customer? Unless they bring up who they are elsewhere on the net (assuming it is not obvious) you simply can't judge such things.
So what do you do; lose money each time this happens? Or take a hard line "we're nice guys and all but, sorry, it's costing us too".
And the happy customer might write about you; but the risk is it sets a precedent. So the next month when another customer screws up they think to try the same tactic - and if you refuse them it's even worse press ("oh, apparently I'm not good enough to be treated that way", "2 tier customer service" etc.).
So what do you do; lose money each time this happens? Or take a hard line "we're nice guys and all but, sorry, it's costing us too".
And the happy customer might write about you; but the risk is it sets a precedent. So the next month when another customer screws up they think to try the same tactic - and if you refuse them it's even worse press ("oh, apparently I'm not good enough to be treated that way", "2 tier customer service" etc.).
It's a minefield all round.