I am playing as Serbia in the year 1370 something...anyways I have 3 traders in venexia and the total trade there is worth 2415 yet I am making a measely 1.95?? Also I had 5 traders in Eguru at some point that had a total trade value of something like 1500 and I was making less than 2 as well. Is this a bug of some kind?
Also, some nations just seem to have low efficiency for what appears to be no reason I can determine. Byzantium and the hordes have terrible trade (like 1%) despite other nations having in the teens with similar sliders.
But as time goes on this will get better. Slider moves and technology will be your friends.
the trade value of the centre of trade is worth 2500 for simplicity's sake
You have 3 merchants there, which gives you 3/20ths of the value anually: 375 ducats. That's about 32 ducats per month
This value is then multiplied by your trade efficiency. For such an abysmal country with terrible sliders and the wrath of god, it's hardly surprising that you only end up with pennies. This can be made drastically better if you invest time, money, slider changes and national ideas into trade. If your Trade Efficiency ends up being over 100%, you can make -more- than the trade value of the Centre of Trade if you hold a monopoly with empty seats (no other nations trading there)
Also note that your merchants will be out-competed by almost any western country who is even slightly advantaged in tech or free-trade.