You can gamble just for fun. I'm doing it, and it really is fun. There are websites like PrimeDice featuring faucets too, so you're getting free money to play with.
Not only primedice but many other sites give your free money to try their games but if your gambling only for fun then you should do it only sometimes instead playing every day because it may slowly lead you to addiction and later on you may start playing with your many and end up losing a lot of money in gambling. So you should very careful even though you're playing with free money.
I think Fortunejack, Rollins and some more sites also give free coins to play. So you can use these sites also to play for fun. With free coin we can just play for fun here, we will not make money. But yes this lead us to addict to gambling. We can not play more time with free coins it will get bored and the games also not exciting because it's free right if we lose also we don't care.
Playing with this free satoshis would definitely make you a gambling addict when you intend to play almost everyday. It wont really hurt us if we lose those money but on the time we won on that free money then lose in the end our emotion would build up to deposit our money to expand your betting style. I believe this kind of strategy of gambling sites help to get players from their site. IMHO