That depends on several factors, of course. In many countries where strong football competitions are held, you see that there is plenty of advertising for gambling in the stadium. However, this is not allowed in all countries. You also have the internet as a powerful medium. Then you end up at Forums and maybe also some marketing tools from Google, but not everything with gambling is allowed there either.
It is true that in football stadiums there are often advertisements for various gambling platforms, but mostly advertisements for bookmakers only, not casinos. Advertising in stadiums and other sporting events is aimed at people who bet on matches or sportsmen and do not play blackjack or poker.