Usually raffles in the US are for charity or fundraising purposes. You can't run a lottery usually, as those run against gambling laws. You can run a raffle, where an item worth $X (and usually donated so X=0) will be given away to the owner of a random ticket which costs $Y. The runner of the raffle sells N tickets. Your profit/fundraising is $YN - $X.
Often raffles are sold significantly below expected value. A popular raffle to support a charity is called a 50/50 raffle. This is where the winner of the raffle receives 50% of $YN, and the charity receives the other 50%. Buying a ticket isn't a good financial decision, but it's for a charity, and you can end up winning, so they are popular.
From what I understand, the game of bingo is similar to lottery in the sense that the participants can and do decide the contents of their tickets themselves. Is organizing bingo OK in the US or does it run against the gambling laws?
Often raffles are sold significantly below expected value. A popular raffle to support a charity is called a 50/50 raffle. This is where the winner of the raffle receives 50% of $YN, and the charity receives the other 50%. Buying a ticket isn't a good financial decision, but it's for a charity, and you can end up winning, so they are popular.