I have earned over 8000 USD from many gambling sites, first you need to choose right games(low house edge games), I have earned most of money from dice site, with 1% house edge. And about 2 btc from blackjack, which has 0.4% house edge, yeah, it means if you have good blackjack strategy and good luck, you can beat casinos.
Additionally, I have earned decent money from sports betting, you need to analyze the match and bet, could win a lot, cos games are random, but sports are not random, better teams/players always win, but unexpected results may eat our money.
If you are telling the truth, then you are lucky or your analysis of sports betting is very good.
There may be ways to analyse sports betting but you won't win all your games.
There are many people have earned a lot from dice sites cos dice has only 1% house edge, and dice has low variance too, I avoid to play slots cos slots have terrible expected return, which means very high house edges, so we may get lucky when we play dice, of course dice is a lucky game, no strategy, only lucky. But if I gamble on slots, I am pretty sure I wouldn't hit any jackpot or big winnings because the house edge is sick high, casinos can eat players' money easily if they are addicted to play slots.
About sports betting, I am up to 3.5btc profits and most of my profits come from tennis, although the odds of tennis are very low to good players, we can still earn lots of money because betting on them is very safe and the profit is very easy.
