One of my neighbours, a million years ago, was obviously addict to the slot machines. He would spend hours spinning in a nearby bar (these machines are allowed in bars in my country of origin) and my take is that he would spend a fortune on it. Once, I passed by and I overheard him saying "I am going to teach this machine who is in charge". It sounded like he was attributing some short of conscience and life to the machine and though he could "beat it". I have observed that many people that gamble are into that type of thinking, that is, it is me against this code and this machine and I can actually break the code and win.
I personally do not play slots, but do you think that is why people like slot machines? Short of breaking their code?
Like any habit forming activity - people tend to drift into slot machines because of "boredom" and a lack of self control compounds the issue. Many people will take up such games because they are trying to fill some sort of emptiness in their life or need some sort of distraction. It starts off very slowly, they might get introduced to a machine on a night out with friends while they're having a great time and then they go back to it trying to rekindle some good memories or perhaps they won a lot on their first go - so think it is easy money. You just need to try to understand the math going on behind it to see that you will never win on such fixed-odds betting machines and it's not worth your money ever trying to find ways to break them.