More on the numbers.
A craps table roll will occur every 30-60 seconds, so assume 45 second intervals.
$100 in play/roll
House edge is about 1.5% on most of the commonly played bets.
If you play for 6 hours, you'll have $100 x 90 x 6 in play, or $54,000 on the table over the course of 1 day.
They expect for you to walk home with 0.985 of that amount, which is $53,190.
You'll have swings where you're way above and way below this, but the casino is expecting to win $810 on you each day for what would seem like a large amount of money bet. Spread that over a few days of play and they're expected win is $1500 to $2000 on $100,000 to $150,000 in total bets.
Just to expand on these numbers, if you're ADT is $810 like the math is showing above, then you can expect about $267 in comps a day. That's enough for a room and about $100 in food every day which checks out with the story.
The only two problems with craps in particular is them rating you properly and often and the small amount of house edge means you need to grind out hours. The first of which is mitigated by throwing them some tips on a semi regular basis. The second is just how much you like to gamble.