The goods transported back and forth between the Alpha Kingdom and the Orc Empire are all in high demand locally, and they've been booked in advance, so there's no need to seek out customers.
I originally thought that as long as I monopolized the supply of orc slaves, customers would come knocking. The reality proved me wildly wrong.
The Nobles of the North and the native nobles operate in two completely separate circles. The news of Baron Katelai holding a large number of orc slaves has only circulated among their own circle, outsiders are completely unaware that he has become the biggest slave trader in the Southeastern Province.
If the news is slow to get around, it wouldn't be a problem. Other nobles will get the message sooner or later.
The crux of the problem is that he sent people to notify some nearby nobles, explicitly telling them that he had a large number of orc slaves. Their response was a dismissive – "Noted"!