What does "You are not in it for nothing" mean?

Question

A: Is it the room?
B: Of course!
B: I will not be able to sleep in that landfill.
A: The theater always sends the authors there.
B: Authors?
B: You would never let Vinaver or Yasmina Reza stay there.
B: You are not in it for nothing.
B: I'm not here for my pleasure.
B: I am invited, but I also have work to do.

What does "You are not in it for nothing" mean?

Answer 1

If you not in it for nothing. You are: In it for something. Meaning: for some reason

Answer 2

B is implying that A is making money from the situation.

To "be in it for nothing" means to do something without being paid or making a profit. To suggest that A is "not in it for nothing" suggests that A is corruptly profiting from giving B a low-quality room.