This is all a ruse to keep you hooked for days and force you to watch hours of commercials that only benefit the developer. He is the only one who profits passively from Bingo Day! Yes, they only launched the game and promised cash rewards that never materialised. They can only look at the money now.
You can spot them pretty clearly as a bingo card is placed on the screen and the games are rendered against the cards as the slot reels are spinning. Some players have played them enough to be able to spot winning/losing patterns on the cards faster than the reels can render.