That's a common expectation in my country. I get to see that a lot and I believe it's because those who gamble and win don't keep their mouths shut.
Some gamblers are not actually the ones that advertise themselves and their winnings to other gamblers. If you are the type who plays bets in betting shops, which are popular around our country, you will notice that when a player wins a bet in that place, irrespective of how crowded the place might be, those cashiers and attendees will somehow talk about the winnings, which others who are there will get the update on, and from there, they will task the player who just won the bet. Sometimes these people do this just to let players know that people still win here.