Once a week, let's say Friday for arguments sake. A server automated lottery is started, Where players have to choose 5 numbers plus a bonus ball number. Players are given a ticket with their selected numbers. They would have up until a certain time on the day of the draw to purchase a ticket, and then a live draw is made. The server randomly selects the 5 numbers plus bonus ball and the winner(s) would be selected and prize given/split between winners. Also, there could be smaller winnings for people having let's say 3 correct numbers from the possible 5 ensuring they have the bonus ball too.

This would give people a reason to have to login all at once for the main draw. Friday's or even Saturdays are when most people have time to be around. Noone else has ever done a lottery system this way before and I think personally, it would generate a lot of interest from anyone who doesn't currently play as much as they could.