OK, thinking twice about it, your argument is valid and the solution appropriate. I see it differently now and I would even say that the sooner the better. It's just that's it's something we're not used to see in the industry.
(I look forward to your comparison, it would be a good read)
For more peace of mind we could change the way the campaign works so instead of allocating a fixed amount to distribute to users every day, you receive a fixed amount at the moment of deposit and you are free to withdraw whenever afterwards keeping the reward. Maybe this is a better solution?
It makes no difference to me but there are people with a different opinion than me of course, so why not ...