They have their strategy, and it's like a commom job, you have to study the market, the odds and find good opportunities to bet
Yes, I do agree. There are people who are into sports betting and they are living their lives because of this. I can say that sports betting will give you higher chance of winning if you are into a particular sport for so long, you already know each player, each team, even their personal lives. Knowing the personality of each player will also help you in determining the outcome of the game. So yeah, some individuals are living their lives out of gambling, not only in sports betting area.