The chat room creates a community and a channel for you to talk to players. I have seen the advantage of these chat rooms, where winners share their winnings with other people and where moderators of the site can do Air drops to encourage people to join the site. <To newbies>

You can even bring in loyalty reward points for regular players and also VIP discounts for the people on the Leaderboards. People can also share their stories. Build the community and people will stay.

I think someone has done this before with Bitcoin and miners found ways to manipulate the outcome. <ignoring specific blocks> You should find the most transparent method possible to do this, because trust is everything in Lottery games like this. I still have my doubts on both Millionairemakers on Reddit and also the Lottery system, built into Freebitco.in.

Provide a chat area for people who are participating to validate that you are playing against actual people and not some automated bots that are pre-configured to enter these games on behalf of the owner to cheat the system. ^hmmmmm^