That IS an interesting business model. I hope he doesn't mind if I adopt and modify it for my own use.
He also only uses White, Green, Brown, Black belt ranks
We also only have a smaller number of colored belts than other dojos. From 10th kyu to 1st dan it's similar to his. At 5th Dan it's white/red (Shihan), then Red Black at 7th and Blood Red at 10th (only one person in our system holds that rank and he's fairly old; mid 70's).