Now, the first question I need to ask is "is this crossing a line" - is it too manipulative... then, if it's not, I need to come up with a bonus scheme.

I was thinking about basing the bonuses on how much revenue has grown past our previous high. (with the number of employees, one guy can really make a big difference, and if we are operating properly, we grow by around 10-15% a month.)

hm. It seems I could pay out on random days on a month that beats the previous months receipts? I think I'd want it to be a 'peak month' rather than a 'peak day' to discourage gaming, I mean, I see how you could queue up customers for a few days... doing this over months could be bad, especially if when the months begin changes randomly.

But yeah, a formula that people can know, with, perhaps, random numbers that aren't known until the period end sounds like the way to go. I think people would mind the manipulation less if it was clear what I was doing and why.