I guess aside from promotions there are money making business that being produce, maybe with those many gambling sites that being offered and with those rumors about game fixing we really can't tell if those big bosses are also involve with gambling.
This will put the reputation of Ramon Ang at risk and I doubt the will do that. Game fixing if it's present in the PBA, then we can say that those who are in control of the PBA are making big money from it, and I think 1 Billion monthly income is just too easy considering the league is already popular that could gather bets outside in the Philippines as well.
I don't know if how he is related to atong Ang, but his operation before which is the E Sabong, he is making a 3 billion pesos monthly income. (GROSS).
And the market is only within the Philippines, how much more this PBA games.
https://newsinfo.inquirer.net/1563433/atong-angs-e-sabong-firm-earns-p3-b-gross-income-per-month-senators-learn