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.