From what I can observe, the site's pretty good at rewarding the right kind of people (bigger wagerers and higher level people), so I don't think bots gain much if anything at all. Rain's always cool and is a small reward for loyal people, obviously, anyone expecting to make money from rain won't get much, if at all.
That said, I have gotten really generous rains in the past from BV! The events are something to look forward to though!
I have seen huge amount of rains here, you could be seriously happy, yet it shouldn't be the main thing. Also, does casino gives from their own share of profit to this rain? Or does investors get affected by it as well?
I think there are new rules to investors now whereby cost from competitions and promos are also taken from our funds (I'm an investor). I honestly haven't really noticed any big difference though.