How much is Nijisanji spending by promoting original songs?
I found this video of a guy rickrolling americans with ads. With $14k per week you can get between 700k to 2.6M views.
Niji probably bought about 400k views for the next wave and they didn't restrict it only to expensive countries. My guess for how much they spend so far is about $6k.
https://youtu.be/Gq8JexGCZEo