How can the gamblers verify that the actual amount of people are receiving the drop or the bonus, if there are no list to verify it?
This won't solve the problem because even if the casino publish the list of winners, there is no way to verify that those winners are real users and not just bots or fake usernames.
To make it as transparent as possible, the casino can partner with a reputable streamer and ask him to draw the winners on a live stream
or use a provably fair system like giving each user a ticket number and use the blockchain (transactions/blocks hashes) to determine the winners.
There's no way of verifying those players whether those are legit or not, thing here is that they do really give that fair service to those who do gamble out.Somehow it do really sucks
when you do know that you are been deceived or believing into something which it isnt really just that fair at all but as i said earlier which there's no way to confirm up these things.
This is why it would be always suggestable that we should really be getting involved into those sites or places which does have that most recognition
or having that reputation.