[annoyn777]

The only way your grandparents were long term slot winners is if they hit a jackpot... I imagine this is the case as you say they went back quite often with 1k. This is called 'giving it back'. It is nice they were able to do this as it seems they enjoyed it, but they were not consistently grinding out a profit at slot machines. Nobody does that, because like other posters have stated slots are designed to take your money. If you sit there long enough, you will lose. If you win a big jackpot or any amount of money that means anything to you my advice is to cash out, head home and enjoy the money.