Great idea Fate! I never thought of that, ah well, I am stupid afterall!

Hi Plebian#10,
It may seem good a settlement being in positives after extermination, yet it is not especially brilliant at all. Surprisingly, if a settlement is in minus figures then it is not actually losing you money at all - instead it is preventing other cities from taking the strain of your empire's expense problems! Unfortunately, in R:TW the income of each individual city is almost irrelevant as it does not represent the income that it the settlement is actually providing - this is because the income that the game calculates includes military expenditure which increases the larger the population become. Instead, I have found that the financial scroll is a much more accurate depiction of what is going on within one's empire. Should anybody desire to work out a more reliable income of a settlement then it often is best to just add up the positive side of the complex settlement details scroll and then subtract the negatives from the end result excluding military upkeep costs. Good luck with understanding this complex post which even I cannot understand, hope this helps you, good luck, cheers!