For SuperFlex DFS contests, OwnersBox takes the difference between (Total Entries*Entry Fee)-Prize Pool. For example 1000 entries at $10 per entry with a prize pool of $900, OwnersBox would take $100.
With Lightning Lineups, any contest that results in a loss, the entry fee will become OwnersBox's.
For Weekly Bracket - H2H contests, OwnersBox takes an industry standard of 10% of the contest entries. The remaining prize pool is handed out to winners.