One of my friends showed me an "casino" app on his phone where they don't give you real money but you can earn (or buy) "premium currency" that can be redeemed

One of my friends showed me an "casino" app on his phone where they don't give you real money but you can earn (or buy) "premium currency" that can be redeemed for various rewards like a free dinner in Vegas or 20-50% off a room, which I would assume Big Fish Casino is doing something similar. It could be that or it could be the big A word that casino's hate (addiction).