What do you mean by how? Of course, they are putting a budget for it every year, and that's how they manage to pay it.
There could be two ways that they are being paid.
Of course, commission based would mean how many members they have raked in through their campaign or something. And for the flat fee is the fixed rate in which there's probably a contract at play, and it is the one being followed.
You can tell an online casino is safe by checking if a reputable regulatory body licenses it, has fair and transparent games, and uses encryption technology to secure your personal and financial information.