Guy doesnt have a house, he just flys around on cheap flights to rack up miles, he has a lot of rewards cards, and does other things to get his miles. He is a bit extreme but I didnt know you could do this.
The last time I had a lot of miles was when I built my house and charged all my materials. I didnt pay for acticket for years. I also heard of guys charging travlers che ks then returning the che ks but keeping the miles.