The most popular lotto in my country is 6/58. It is always blockbuster because of its huge rewards, it is legal because the government of my country controls it.
What your country is?. Lotto in my country has been banned 30 year ago. Ilegal right now, but still people can buy it on background and police always patrols to catch dealers who sell it online and offline the market place.
I think lotto for the entire country should focus also on providing help for charities and to donate some portions of the money to people in needs. That is why lotto in our country is still alive and many people are still playing ball game, because mainly if the lotto is focused on just earning profits, and government isn't benefiting from it, they might view it just a gambling platform that isn't healthy for the people.