Many people are in doubt about the fairness of the lottery.
... if someone can figure out a way to implement a provably fair lottery with a variable number of tickets given out each round, I would be happy to implement it. So far I haven't been able to figure out how to do it myself.
Maybe you should use some third-party intermediary for generating random user IDs for the lottery? For example, there is "Audited Lotteries and Sweepstakes" option in random.org.
https://www.random.org/guides/draws/That would not help make the lottery more fair as I can always insert user id's of accounts created by me to the list. Also, that option does not allow for a user having multiple tickets. Thirdly, I have to trust that random.org will generate the numbers fairly and not manipulate the results.
Also, as far as I can see, the results will not be public and people will need access to the random.org account to verify the winning numbers.
Yes, I see. Then, you could offer some kind of incentive(additional tickets, bonuses, etc.) for the lottery winners if they post about their winnings here?