This kind of results is very rare and many gamblers have been gambling on free spins and casino games just to have this kind of results. I never new that free spin can give this kind of winning although I have seen the one that is much more bigger than this but was not a fee spin. This is the kind of luck we have been hoping to get as a gambler but I think this is just luck and nothing more. This kind of winning happens once in a while mostly to gamblers that have not plan or this kind of an expectation. Hope to see more of this kind of result.
Of course it's luck. Slots are RNG-based games, solely based on luck. There is no skill involved when spinning the reels in slot games. You only have to decide how much money to stake per round and perhaps the number of paylines.
Getting to the free spins bonus rounds is the entire purpose of the game. That's where the biggest wins are hiding. They usually entail certain features that are not available during standard gameplay. For example, you will find multipliers that stick to their positions during all bonus spins, significantly increasing your profit. You can also get special symbols, giving you even more free spins. Then you have wild symbols, helping you win even when you don't have all the needed winning combinations.
All that time, you aren't spending your own money.