I believe he was indicating that he did both matched betting and got casino bonuses through playing black jack.
Tis less profitable now but essentially online casinos offer signup bonuses and you need to have bet over a certain amount in order to claim the bonus.
Blackjack is a game with only a small house edge when played using basic strategy (it varies according to the rules in place at the particular casino) - essentially if the bonus is larger than your expected loss would be in playing enough hands of blackjack to meet the withdrawal requirement then its a +ev proposition to try and meet the withdrawal requirement (assuming its a legit casino with proper RnG etc..).
You can obviously lose money whilst chasing an individual bonus (there is some variance) but as long as chasing each particular bonus is +ev then you should make money in the long run. Conversely you could end up being rather lucky making money from blackjack while attempting to meet a particular bonus requirement and then claiming the bonus too...
Thing is the amount you need to play to claim the bonus has increased a fair bit, some sites have stopped allowing blackjack for bonuses (you could try a low edge video poker variant). The time to do this was really 10 years ago though if you're a student and have some free time then I guess bonus bagging and matched betting might still be worth a shot.
The problem is that in the past it was mostly people who had an interest in gambling who'd spotted the opportunity to make money from bonuses who were doing it, then people discussed it on forums and later people wrote idiots guides to it etc.. you then end up with a whole bunch of people, most of whom would have never had the foresight to come up with anything like it themselves*, abusing bonuses at casinos etc.. obviously the free money decreased somewhat. Casinos want to use freebies for marketing but don't want to open the floodgates and start hemorrhaging money to a whole bunch of people mindlessly following a blackjack basic strategy card.
(*not that it required much tbh.. I'm pretty sure plenty of people around the world saw the opportunities to take advantage of casino bonuses back in the day...)
Wow, thanks for the very detailed description!!
I think you hit the nail on the head there - in the past, it was mostly people who had an interest in gambling which is probably why it has stayed that way. However I definitely think that bonus bagging is going to be a huge trend - like it was with moneysavingexpert - when that first started, only the super savvy, accountants, lawyers, IFAs knew what is the best way in which we should save our money, as well as our consumer rights.
Websites like Fixtheodds.com are obviously trying to tap into the market of people who aren't pros or gamblers - after all, you make a profit, they make profit since they get a commission at the betting exchange.
Having read what you've said about casino offers, it seems that there's definitely more bonus bagging opportunities out there. However I haven't seen any websites that offer similar 'idiots' systems' for casino offers yet...
I guess you're right - bookmakers can't be overly happy, however they're probably in some sort of hope that some people might end up putting in the odd bet anyway.. Also, the chances that you're going to lose at the bookmaker (so good for them), is equal to that as if you'd just gone to a bookie and placed a normal bet...
For the betting exchange - they couldn't care less! They take commission from any winnings...