I've heard some people say that merchandising on NT players are so little that it's insignificant. But you get close to 30% of merchandise increase, and that is not a bad figure in my opinion.
Well it would be a great thing if someone made a study of it but I know the amount of merchandising you get is affected by three things.
1) You get a lot merchandising if the player is playing for your NT, the amount you get for playing for a foreign team is trivial.
2) The salary of the player, this is especially affected by U21 players who often have fairly low salaries so the boost is low.
3) How much the player played for the NT in the previous week. So if he got a DNPCD or 5 minutes you get nothing or so little it is trivial.
So if you have a $100,000 player starring for your local NT you will get a massive boost, Kynlala Knights, Smeltz Troopers and Western Titans had this. If you had a $20,000 playing moderate minutes for the U21 team you get a small boost, this was me. If you have low salaried players playing for a foreign team you get very little, I remember discussing this with a team that had three foreign NT players but was still below league average in merchandising.