Who do you think are the higher rollers...
Gamblers online at bitcoin casinos.
or
Gamblers that play at physical casinos ?
Finally, why do you think that physical casinos attract more or less people (excluding the fact that bitcoin is not mainstream)
i am sure that people are making a lot bigger bets on real physical casinos especially those in Las Vegas, because there are a lot of millionairs playing at those casinos while bitcoin (online) casinos are only attracting small time gamblers so far.